Estimating measurements without a tape measure

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Blog entry by Stevinmarin posted 06-10-2010 07:53 PM 15634 reads 0 times favorited 24 comments Add to Favorites Watch

Just a few ways I estimate measurements. If you have any other neat ways to measure things, post them in the comments!


-- Entertainment for mere mortal woodworkers.

24 comments so far

View a1Jim's profile


117626 posts in 3964 days

#1 posted 06-10-2010 08:04 PM

Good one Steve we tend to forget about some of the tools we have built in for measuring. I regularly use measuring blocks or gauges that come in a set 1/8- 1/2” you can make your own by buying some key stock at a hardware or automotive store. another good way to measure is to use open ended wrenches when turning if you want a 3/4” tenon you just turn it down until the 3/4” socket fits. I’ve also seen people use the thickness of wrenches as a height gauge on table saws and router bits.

View littlecope's profile


3072 posts in 3889 days

#2 posted 06-10-2010 08:16 PM

Years ago, at a restaurant I worked at, they were going to buy some new plates (to replenish the stock).
I thought they looked to be 8” rounds, but there were various guesses by everyone in the kitchen, ranging from 6” to 9”...
One of the Chefs pulled out a dollar bill, held it to the plate, and declared, “These are 8” plates.”
Of course I said, “Huh?! What?!”
He said his Dad, an avid fisherman, had told him many years before that all U.S. currency is exactly 6 1/4” long.
I’ve used that one a hundred times and it’s as accurate as can be… :)

-- Mike in Concord, NH---Unpleasant tasks are simply worthy challenges to improve skills.

View Cozmo35's profile


2200 posts in 3423 days

#3 posted 06-10-2010 08:36 PM

Penny = 3/4
Nickel = 7/8
Dime = just under 1/2 (I forget the exact and I don have one with me)
Quarter = 1 inch

-- If you don't work, you don't eat!.....Garland, TX

View michaelray's profile


232 posts in 3841 days

#4 posted 06-10-2010 08:44 PM

Great question. I think this is something most of us take for granted. I’ve used the dollar bill before (although I rarely carry cash anymore – I should measure out a credit card). I sometimes step off distances – I wear a size 12. Sometimes I use the carpenter app on my iPhone – is that high-tech cheating?

-- [email protected]

View flyfisherbob2000's profile


81 posts in 3374 days

#5 posted 06-10-2010 09:12 PM

a dollar bill (never find any bigger denomination in my wallet) is 6-1/8” long, 2-5/8” wide. I use the bills to measure short lengths all the time

View Woodcanuck's profile


128 posts in 3387 days

#6 posted 06-10-2010 09:12 PM

Luckily my shoes end up being roughly 12” long….I use that all the time, along with the 8 1/2×11 sheet of paper trick…you can always find paper.

Photographs are usually a standard set of sizes as well, 4×6, 5×7, 8×10, etc….

I happen to be roughly 6’ tall, and coincidentally my arm span (fingertip to fingertip) is the same as my height. I believe this is roughly the same for the average person. Of course…I look silly lying prostrate against whatever I’m measuring….but it works.

My last crazy trick is to use a tape measure…. :-)

-- Ian - Life's a game, if you don't play, you can't win.

View Dan Lyke's profile

Dan Lyke

1520 posts in 4512 days

#7 posted 06-10-2010 09:20 PM

My outstretched arm span is pretty close to 6’, which is handy when doing rough “what furniture will fit where?” or “how long is this board from my wood stash” calculations.

And of course as my woodworking gets better I find myself using story sticks or other unitless measurement rather than tapes. A knife nick on a piece of scrap wood is way more accurate than a tape measure.

-- Dan Lyke, Petaluma California,

View bobkberg's profile


439 posts in 3460 days

#8 posted 06-10-2010 09:28 PM


Ceiling tiles are usually 1’ X 1’, 2’ X 2’ or 2’ X 4’, rarely 4’ X 4’

I use some others, but you folks beat me to them, or taught me something new.

-- Bob - A sideline, not how I earn a living

View poroskywood's profile


618 posts in 3751 days

#9 posted 06-10-2010 09:40 PM

I’ll also take note of the length of items or jigs I use regular in my shop. Example from saw blade to the end of my crosscut sled on the right side is exactly 12” on the left it’s 24” on the money so I line a square board up with the edge of the sled using the feel from my fingertips and Voila it’s exactly 1 foot or 2. Later Dudes!

-- There's many a slip betwixt a cup and a lip.--Scott

View littlecope's profile


3072 posts in 3889 days

#10 posted 06-10-2010 09:45 PM

You mean I’ve been off by an 1/8” all this time!! No wonder why my stuff never goes together… :)

-- Mike in Concord, NH---Unpleasant tasks are simply worthy challenges to improve skills.

View chrisstef's profile


17914 posts in 3393 days

#11 posted 06-10-2010 10:44 PM

I like to use the span on my out stretched pink to out stretched thumb as a guide for approximately 8 inches … i like to call it the italian tape measure.

-- Its not a crack, its a casting imperfection.

View Chase's profile


448 posts in 3413 days

#12 posted 06-10-2010 11:11 PM

bravo on the carol quotes! I have used a few of these before, especially the playing cards one. playing cards are the best!

-- Every neighborhood has an eccentric neighbor. I wondered for years "who was ours?" Then I realized it was me.

View JJohnston's profile


1622 posts in 3678 days

#13 posted 06-11-2010 01:45 AM

See this post for adventures in using floor tiles as a tape measure.

-- "A man may conduct himself well in both adversity and good fortune, but if you want to test his character, give him power." - Abraham Lincoln

View TopamaxSurvivor's profile


18567 posts in 4063 days

#14 posted 06-11-2010 03:03 AM

I measue wire with my 5.5’ arm span or one arm to nose =3’.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View canadianchips's profile


2626 posts in 3384 days

#15 posted 06-11-2010 03:33 AM

I few years ago I had a kid working for me. After 3 years of trying to pass grade 9, he quit school. Reading, writing and numbers were a problem for him. His first task was to cut 8ft 2×4 ’s in half. After an hour of failing badly I had to step in and help. 1/2 of 8ft is 4 ft. Whats a foot he asked ?. Okay 8ft is 96”, 1/2 of 96 is 48”. Whats an inch he asked ? I thought to myself,O crap this is going to take time. I grabbed the 8ft 2×4 laid it on my cutoff saw and showed him we will cut in half like this. (Eyeballing, no numbers to confuse him, then use first one to mark out the rest.) So I cut, he wondered if it was in half. I stood the 2 pieces on the floor and they were exact. His jaw dropped and was amazed at how I did that. He folllowed me the entire day listening and learning things. (I was saying to myself, I have more luck than he had brains) What he didn’t know is I have saw cuts on fence of my saw at 16” 24” and 48”.
Tricks of the trade that my older carpenters shared with me !

-- "My mission in life - make everyone smile !"

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