# help with measurements



## trojan62 (May 12, 2011)

hi all,
hope someone can help.
ive only been doing woodwork for about a year and i dont think im too bad at it, but one thing i always seem to struggle with is measurements. what im talking about are things when it says measure 1/16 or 1/8, things like that of an inch, these mean nothing to me. does anyone have a help guide or sheet explaining thses sort of measurements.
soory if i seem a bit dense on this subject, but id like to learn this sort of stuff better.

cheers chris.....


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## Ben I (May 21, 2010)

The imperial main length measurement if the foot. It was originally equal to to the length of an English kings foot. Presumably his foot was kept frozen in case someone needed to do some calibrations. 

Seriously, there are any number of split scale metrc/imperial measuring devices available. I like my cheap electronic calipers. Take a measurement and push the button to switch from metric to imperial and back. I personally rationalize imperial 
measurements to metric before I start the project. The heck with fractions of an inch.

Regards
Ben


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## kp91 (Sep 10, 2004)

Chris,

a program I use all the time, a great download for converting Standard/Metric

Convert for Windows - joshmadison.com

Free fractional calculator

Pattern-Making Calculator

Both of these tools are great for working back and forth between fractional, decimal or metric dimensions.

If you're lucky enough to have a good hardware store around, you can find a poster sized tap/drill chart which makes for easier conversions as well.

Hope htis helps,


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## Quillman (Aug 16, 2010)

"/16 or 1/8, things like that of an inch, these mean nothing to me."
******************************
And they'll mean even less without metrology (measuring engineering) skills, and that stuff is not to be found easily. You'll learn the arithmetic of splitting an inch up in an afternoon of study.
But can you measure to the nearest 1/32 whether inside or outside of the assembly.
How do you mark and scribe from one hole to another?
How do you drill and saw consistantly? Can you calibrate your hand and machine tools so your cuttings are predictable? Are your jigs adjustable and can they be set to your needs?
All related to measuring and layout skills.
I haven't a clue where to look either.
This is the stuff of woodworking, however!


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## Phil P (Jul 25, 2010)

Hi Chris

I'm also in the UK and I'm old enough to be comfortable with both systems. 1/8in is actually 3.2mm, 1/16in is 1.6mm. In metric terms we often work ro 1mm or 2mm on most jobs - and then fit as required! If you are starting with an Imperial drawing it may be better to convert the drawing to metric before you start, or to buy yourself a tape measure with both Imperial and metric markings side by side - most manufacturers still sell them.

If you think that's bad I sometimes work with guys who insist on giving me measures like 45 x 1033 when they mean 24 _inches_ x 1033 _mm_, depending on how they easily they can take a measure with a tape.This is known to lead to one or two amusing errors..... Which is why I've started using a laser rangefinder on some jobs when I'm the guy on the scaffold tower!

Regards

Phil


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## Ben I (May 21, 2010)

kp91 said:


> Chris,
> 
> a program I use all the time, a great download for converting Standard/Metric
> 
> ...




Doug 

I have down loaded the unit conversion programs which you listed.

Many thanks for the information.

Ben


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## gwizz (Mar 3, 2012)

*Working with imperial measurement / fractions*

For our UK friend :

Out here in the Northern colony (forgetting the old prison colony in the South Pacific – they are generally too busy drinking beer to care ) we live in the great white north and have to be nimble to avoid being stepped on the lumbering elephant to our south. 

We use both metric and Imperial ( us old folk anyway as the kids only get metric in school ) Canada went official metric back in the 1970(s) but sine about 80% of what we export goes to the US and they backed out of changing from imperial to metric our whole country ( construction and manufacturing ) was stuck with the expense of converting equip to metric and then duplicating or converting back to imperial when it dawned on everyone that our main customer was staying imperial.

It has since, proved to be a blessing as it has allowed Canada to improve it’s exports to the rest of the world ( USA is still larger than all others combined ) and we continue to expand on alternative trading partners.

I have to deal with my daughter and son in law who both have interests in wood work and home fix up etc. but they were educated totally in metric ( our brilliant educators think Canada switched when the reality is, in the day to day working world of construction etc. is still imperial ) young people, no mater how smart are only educated to divide and multiply by 10 ( unless there are machine level programmers dealing in hex decimal and then 16 is everything )

I explained working with fractions and practicing it as follows :

Forget attempting to convert from one to the other unless you have no choice and have a metric tool to make something that must be in imperial or visa versa.

Generally consider only ( none of the following are seriously accurate )
A metre is the same as a yard ( it’s actually a little longer )
3 feet to a yard ( three BIG feet to a metre )
And 8 mm wet suit only keeps you as warm as a 1/4" inch wet suit 
A ¼” inch bearing fits nicely on a 8 mm shaft.
If the speed limit is 60 mph you’ll get a ticket if your going much in excess of 100 kph

I keep an old fractional Caliper refurbished and clean as it I use it 48/12ths more than my shiny new digital caliper as inches by the 10s requires the conversion chart I have taped to the wall and is a lousy way to deal with imperial.

To sort out using Fractions sit down with an imperial ruler or yard stick (a short metre )

1 ft = 12 inches 
When you doing wood working you are generally working to not much smaller than 1/16ths, unless you’re one of these guys with a gazillion $ precision guide fence and more time than the norm. A big 1/16th or a little 1/16th is a 1/32 so you really don’t need to consider anything but that 
You will be working with
Whole Inches ( a dozen or 12 to the foot )
1/2” inches ( the inch cut in half )
1/4” inches ( the inch cut to quarters or the ½ inch cut in ½ )
1/8” inches ( the inch cut in 8ths or the ½” cut into 4th or the ¼” cut in half. )
1/16” inches ( the inch cut in 16ths or the ½” cut into 8th or the ¼” cut in 4th & the 1/8” in half ).
1/32” inches ( is a small 1/16 or half of a 1/16th )

If you going less than then you’re in the wrong hobby and should go over to your buddies at the machine shop for equipment, material and project ideas.

It you have a fractional number and want to cut it in half keep the same value as the top and double the bottom.

If you adding values get them to the lowest common denominator before you add them together and then bring the result up to the largest denominator you can get.

While this is all no brainer to the old timers it does require a little practice by the young or pure metric educated and you won’t get comfortable unless you stop trying to convert it in your mind or relate it to exact metric.

Much like dealing with Fahrenheit and Celsius temperatures -40 is the same in both temperature scale and the freezing point of water is 32 degrees Fahrenheit or 0 degrees Celsius, with humidity 100 degrees Fahrenheit and 40 degrees Celsius is hotter than hell. You don’t want to be outside much with -40 and wind no matter which scale you use and thats generally all you need to know.


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## Phil P (Jul 25, 2010)

Hi Richard

Thanks for that, it was a real tonic seeing the topic handled with so much elan. Not to mention being an education on the subject of Canadian international relations...... :haha:

Regards

Phil


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## Mike (Nov 22, 2004)

Chris, to help you understand fractions better see if this makes sense to you:
The bottom number of a fraction tells you how many equal sized units it takes to add up to the whole amount. The top number tells you how many of these equal sized units you need to count. If you slice a pizza straight through the middle you end up with two pieces which equals the whole pizza. You share with a friend and you each get one half of the pizza. Expressed as a fraction you would each get 1/2. If you were sharing with 3 friends you would cut the pizza into 4 even sized pieces and you would each get a quarter of the pizza or 1/4.(See note below*) Now let's cut the pizza into 8 equal sized pieces or 1/8. Of the 8 people invited two don't show up. You have two pieces left over, 2/8 or 1/4. If you take them for later plus the one you ate you got 3/8 of the pizza. Apply the same idea to linear measurement and you are in business.

* In the US pizza is commonly cut into 4 pieces and sold as a "slice" for lunch. Many people each day order a slice for lunch. I guess the rest of the world orders 6.35 mm's of pizza? :jester:


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## DaninVan (Jan 1, 2012)

Chris; I'm a bit shocked. Never mind measurement systems, are you in fact saying that the UK education curriculum no longer teaches fractions?! 
Conversion of fractions to percentage and vice versa?
To use Mike's example, "We'll put three eighths of the pie away for lunch tomorrow and serve the other five slices."


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## gwizz (Mar 3, 2012)

Hi Phil ……..

Glad to hear I didn’t offend anyone, mind you once the Aussies start throwing ( whatever their equivalent of snowballs are ) watch out I'll be running for the bush to hide.

I notice you uploaded some equipment manuals which are tools you presumably own or use and I was fascinated by the AP98 lipping planer. I am not a trained or educated woodworker and generally putz in my basement with projects that come to mind ( I hate plumbing and house construction ) and will spend weeks building a plant stand / toy box / game board / tea cart / etc. etc. ). Prior to tonight I had never heard of a lipping planner, they no doubt have them here but it’s not an item I have ever seen in general retail. 
I am currently doing and entertainment wall ( TV stand / toy cupboard – aquarium base – book shelves and media storage unit ) and to do the project I determined I would use a combination of glossy finished maple and tung oiled – dull oak with tops of edge to edge glued up panel, but sides, shelves & doors etc. of matching plywood. Having never had luck gluing on plywood edging ( either chipped or pieces came loose ) I decided to use ½” and 3/4” wide lumber clamped and glue like lumber panel gluing. The resulting problem of planning or sanding the oversized 9/16” and 13/16” ( back to our fraction usage ) thick lumber down to flush with the plywood without damaging the plywood was the issue. This lipping planer is exactly the tool I needed but didn’t know existed.

I solved the problem by making a jig for my router table to use with a long 3 bladed edging bit . Unlike the planer that sits on the surface so the blade won’t dig into the plywood, by problem was keeping the wood straight up and perpendicular so that the bit wouldn't gouge the plywood or taper the edging lumber. Some Baltic birch, a 1 ft ( 12 inches ) or Aluminum square tube and 2 roller skate wheels solved all the problem. The attached photos show the gig which uses the roller skate wheels ( I still have parts around from my skating days ) to force the plywood against the vertical back of the jig to keep it squared up, the back plate leave a gap at the bottom so the over sized edging doesn't force the bottom out from the back plate .

As usual I find I have re-invented the wheel long after someone else had and mine version is crude compared to what’s already out there. The good new is it works and I'm 3/4 through building the set without ruining some real nice cabinet grade plywood.


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## jw2170 (Jan 24, 2008)

> forgetting the old prison colony in the South Pacific – they are generally too busy drinking beer to care


Right on, Bud.........Helps to work out what is important in life ( cutting to 0.0011" or cutting to fit LOL)....


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## jw2170 (Jan 24, 2008)

> If you adding values get them to the lowest common denominator before you add them together and then bring the result up to the largest denominator you can get



I agree, but if one cannot understand basic fractions, how are they able to calculate the lowest common dominator. The most basic of maths is no longer taught in many school systems these days. :sad::sad::sad:


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## gwizz (Mar 3, 2012)

" but if one cannot understand basic fractions, how are they able to calculate the lowest common denominator. The most basic of maths is no longer taught in many school systems these days."


Hi James… 
I agree too, my youngest daughter was 8 years old ( now 34 ) and smart as a whip when we figured out she was bluffing and couldn’t read and analog clock. When we check at the school we found they had Digital clocks in the whole school as we did at home. My daughter covered it up like people cover it up when they don’t know how to read ( doesn’t mean they aren’t smart ). We went out a bought some analog clocks for the house and to the schools credit once the principal looked into it, my daughter was not alone, so they converted the school to analog clocks within a couple of months.
We seem to be cranking out kids who can do advanced calculus but unable to make change unless a computerized cash register screen show them the net subtraction of the money tendered versus the selling amount of the burgers and fries.

:yes4:


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## harrysin (Jan 15, 2007)

Come on guys, Chris. is having us on and you all fell for it!


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## jw2170 (Jan 24, 2008)

Maybe, Harry. But my comments still stand......

Look how long your posts regarding metric -v- imperial continue...

It does seem that a few members have strong feelings in regard to the deterioration of standards these days...


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## Marcel M (Jun 14, 2012)

This will help.

Reading a Tape Measure - YouTube


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## trojan62 (May 12, 2011)

with regards to harry, i wasnt having anyone on, i was just asking for some help, i thought thats what the forums were all about.

chris....


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## jw2170 (Jan 24, 2008)

trojan62 said:


> with regards to harry, i wasnt having anyone on, i was just asking for some help, i thought thats what the forums were all about.
> 
> chris....


Can I ask, Chris, what did you use for measuring the woodworking you have done so far.

Even a simple steel rule like this should have at least 1/16" markings.

Q622 | 70-622 Steel Rule | machineryhouse.com.au


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## Phil P (Jul 25, 2010)

gwizz said:


> mind you once the Aussies start throwing ( whatever their equivalent of snowballs are ) watch out I'll be running for the bush to hide.


Hi Richard

If the adverts are to be believed it'll probably be Fosters cans...... :haha: (empty, of course)

The lipping planer is certainly an oddity but if you are doing volume lipping it is well worth the money. I bought mine because I was forever having to cut down pre-made door blanks to fit existing openings and then relip with hardwood (the core often being nasty chipboard). Doing one or two by hand is OK, doing 50 or so isn't much fun, hence the lipping planer. BTW the last pass is always with a low block plane because I tend to leave the lip about 0.3mm proud to avoid damaging the face of the door

BTW, neat jig! Looks a bit like the industrial machines they used to sell for the task. I'd previously worked out how to do the task like you - router and jig, although my jig was simply a piece of MDF screwed to one side of the baseplate so that the router (hand held) ends up with a stepped base. Works OK, but not as quick as the AP98

Regards

Phil


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## mgmine (Jan 16, 2012)

Get a tape measure that has both scales on it. A cheap one can be bought for one dollar. An inch is divided into equal parts. So if you see 1/16" it means that 16 of them equal 1 inch. If it says 1/4 then 4 of them equal 1 inch and so on. How many 1/2" would there be in an inch? Simple there would be 2 of them 1/2 and 1/2 = 1.


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## harrysin (Jan 15, 2007)

trojan62 said:


> with regards to harry, i wasnt having anyone on, i was just asking for some help, i thought thats what the forums were all about.
> 
> chris....


Please accept my sincere apologies Chris, I did check on your public profile but it was blank and this is what led me to think that it was a hoax post. I have on many occasions said on this forum that I don't consider any question to be stupid and over time have demonstrated great patience ensuring that when I answered questions that I considered myself qualified do so I did so in a professional manner. Had your profile detailed your age, background and woodworking experience, also the tools that you have at your disposal, then my answer would have been very different. Once again Chris. please accept my apologies for being flippant.


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## trojan62 (May 12, 2011)

no problem harry, like i said in the original post, im a bit dense at measurements and i wasnt the greatest at maths at school, but as regards measurements im sure ill get better. this is a great site for help and my thanks to the people who have replied so far.

cheers
chris......


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## Danman1957 (Mar 14, 2009)

I can understand your confusion and I think the best solution if you are working off a plan, is to convert the whole plan to metric before you start. Wood working is my passion but I sell tons of steel for a living. I am fortunate to be knowledgeable in both Imperial and Metric systems and we actually have frequent requests where customers send us drawings to quote and they indicate some parts in each system. Talk about confusion !!!! I have been in the steel business 31 years and have lived through the supposed transition to Metric, the funny thing is that to sell Metric steel we must import it from Europe. So during the week I am constantly using both systems but on weekends it's mostly Imperial. If you go to a lumber yard or mill you are still buying in imperial. Most plans we use for our woodworking projects are with imperial measurements and therefore it is quite simple, but I have to help my children (32 & 25) and my grandson 10years old with the conversions and surprising that my grandson knows more about Imperial than his mom or uncle !!! I guess schools are teaching some Imperial systems now. If converting is difficult I agree that a caliper is an excellent tool to help and I use it regularly at the jointer or planer for it's accuracy. 

Good luck


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## JOAT (Apr 9, 2010)

Or, get yourself a decent little steel rule, with metric on one side, and imperial on the other. Then you can actually see how large (or small) 1/16" and 1/8" are.
And this explains why you guys use metric. http://www.bobanddoug.com/sounds/gwn/mtrcbeer.wav


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## Leifs1 (Dec 16, 2009)

Mike said:


> * In the US pizza is commonly cut into 4 pieces and sold as a "slice" for lunch. Many people each day order a slice for lunch. I guess the rest of the world orders 6.35 mm's of pizza? :jester:


Hmm Over here i DK we can only buy one hole pizza but we can buy a small pizza or a big one. We can also cut into 4 equal parts because we do use fractions her as well. But fractions af what ?
1/4 of an inch may be 6,35 mm but a 1/4 of a pizza is something else or we would be starving :stop:

regards Leif


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## sailboat (May 18, 2011)

36918 Precision Brass Setup Bars In Stock $19.99 Each
These bars are available from "Rockler" and are 1/8, 3/16, 1/4, 5/16, 3/8, and 1/2 inch
With them you can see the size and measure them with a ruler, caliper, etc.
You can become familiar with the actual size of these measurements and that should help.
Amazon will probably have them for less money


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## OPG3 (Jan 9, 2011)

Chris,
My simple solution will work for anyone of any age. Become the owner of TWO TAPE MEASURES one metric and the other factional. If your project is metric, use the metric tape measure. If fractional, use the fractional tape measure. I work with customers all over the planet and have found the single tapes with both methods make one very error-prone or it slows one down. Metric is a much better system when conversion to weights and volumes gets involved, but when only considering linear measure - either way works about the same. With a dual system tape measure, you will stay confused. Eventually, and over time you will learn to do conversion estimates. The systems are independant and therefore do not lend themselves to easy conversions. One foot is about 300 mm..


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## AndyL (Jun 3, 2011)

OPG3 said:


> Chris,
> My simple solution will work for anyone of any age. Become the owner of TWO TAPE MEASURES one metric and the other factional. If your project is metric, use the metric tape measure. If fractional, use the fractional tape measure. I work with customers all over the planet and have found the single tapes with both methods make one very error-prone or it slows one down. Metric is a much better system when conversion to weights and volumes gets involved, but when only considering linear measure - either way works about the same. With a dual system tape measure, you will stay confused. Eventually, and over time you will learn to do conversion estimates. The systems are independant and therefore do not lend themselves to easy conversions. One foot is about 300 mm..


I like that suggestion, and I wish single-system tape measures were easier to get in the UK. Every tape measure and ruler you find in stores here is metric on one edge and imperial on the other. Metric-only tapes can be found from internet suppliers if you hunt around, but two of the biggest mail-order tool catalogues that I happen to have at hand don't have any. And to get an imperial-only measure? I think our only options there are probably ordering from the USA, or hunting down an antique item!


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## harrysin (Jan 15, 2007)

trojan62 said:


> no problem harry, like i said in the original post, im a bit dense at measurements and i wasnt the greatest at maths at school, but as regards measurements im sure ill get better. this is a great site for help and my thanks to the people who have replied so far.
> 
> cheers
> chris......


Chris.,first of all thank you for being so gracious in accepting my apologies. When I left school in Manchester England in December 1949 my grasp of the English language and maths were almost non-existent because all I was interested in was the wood/metalwork shop and the physics lab. My physics master found a job for me as an improver radio and television technician. It soon became obvious that if I was to advance with my electronics study I would have to come to terms with maths and English in order to write my lecture notes and submit assignments that my teacher could make sense of. I now had a REASON to improve these two subjects and things that I had been "taught" started to click in my mind. The result was that I progressed very quickly and by age 20 was managing a service department where every technician was many years my age but I had their respect because it was obvious that I was capable of doing everything that I expected of them.
The reason for the above true story is to make you realize that now you have decided to make woodworking your hobby, you have a reason to learn basic maths, and I emphasize the word BASIC, once you start, I'm sure that one day in the very near future something will "click" in your mind and it will start to make sense.
Assuming I haven't sent you to sleep, I must tell you that if you go through some of my many photo-shoots with full explanations and you have any questions, you can post them on the forum, send me a private message or email me direct as have many members in the past, this way I'm able to illustrate my answers, and let's face it Chris. a picture is worth a thousand words. Because I tend to mix metric and Imperial, these shots show what I use most of the time.


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## BRAVOGOLFTANGO (Oct 11, 2012)

Hope you found what you were seeking Trojan. I'm trying to find some good old Navy books I have for deep sea diving school and hull tech training that had some good basic math formulas, etc. I sometimes find myself needing some basic math formulas for simple projects and invade Google for resolve, with luck @times and not so much other times. I like the 3 links provided here, but am still seeking a good site for construction math. I used to have some good manuals from Deep Sea Diving School & Hull Technician when I was in the Navy & have misplaced all but my Dive Manuals which had some good principles & formulas. My shipbuilding days post-Navy career resulted in learning a ton of awesome math layout formulas, but I'm in aerospace now and have since forgotten what I learned, much of it anyway. Gotta brush up now that I'm into this woodworking as of late.

Anyone with some good advanced math links for woodworking or even general layout sites, would be appreciated.


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## DaninVan (Jan 1, 2012)

Hey, Brett;
do you have this one?
Amazon.com: 0806958022: Books
And this pocket sized (literally!) reference ?
Amazon.com: 0962235903: Books


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## BRAVOGOLFTANGO (Oct 11, 2012)

DaninVan said:


> Hey, Brett;
> do you have this one?
> Amazon.com: 0806958022: Books
> And this pocket sized (literally!) reference ?
> Amazon.com: 0962235903: Books


No Dan, but soon as I get home I'll check them out and order, thank you sir.


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