How to Measure Things Without a Ruler





Introduction: How to Measure Things Without a Ruler

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Some of us don't always carry a tape measure/ ruler/ caliper with us all the time, and are at a loss when we need to measure something. In this instructable, I'll help you solve this predicament by effectively measuring things you usually, if not always have within arms reach: credit cards, dollar bills, coins and cell phones. This way, when you need to measure something (and don't have a ruler handy) you can use your standardized objects to measure against.

Let's get started!

Step 1: Whats in Your Pockets?

Look into all your pockets right now, likes are you probably have some crumpled dollar bills, a credit card (or business card) some loose change, and your cell phone. We are going to measure these articles and use those measurements to serve as makeshift rulers.

Step 2: Measuring Up

A typical credit card measures about a bit under 3.5 inches wide by 2 inches long.

A U.S bill note measures 6 inches wide by 2.5 inches long

A U.S quarter dollar (new or old) measures about 1 inch in diameter

An Iphone 5S measures 2.3 inches wide and 4.9 inches long

Step 3: Dollar Measures Up

I found that after measuring the dollar bill was probably the best makeshift ruler, as it is a 1/2 foot, and because it is foldable, I could easily figure out any fraction almost exactly.



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    35 Discussions

    I'm insulted by the idea of being illiterate. Everybody Knows! Everyone who has been educated and attended school and graduated. To Identify One Inch: First, you will take a perfect circle and make a center in it. Or use a compass rose and draw a circle. The bigger the circle the more accurate the one inch will be. However, when using the compass rose circle, no matter how big the circle is; one inch will always equal one inch! I'm not going to reveal the buisiness secrets to the compass rose, which in mapping is used to mark one inch to begin with. It's just a big picture of reading I don't want to do, or use when I want the answers now, without uelling ad screaming and acting like a mad scientist! Good Day, and Bidd Well!

    2 replies

    Sure. Where in my house will I find my compass rose? Seeing as I don't have one.. I guess I'll just use a dollar bill. -_-

    I'm not sure how this insinuates you are illiterate... but if you were not in-need of quick, on-hand methods to find an object's size, perhaps it's not an instructable for you?

    Just wanted to messure my pnut dont no if its doing the job:(


    1 year ago

    That poor 20 dollar bill.

    I like the US bill thing... I think im gonna mark one out at 1/2" intervals and fold it up and just keep it in my wallet or folded up flat in between my phone and its case! thanks!

    I got one of those Swiss Army Knife credit card sized gizmos with me all the time, its about the size of a credit card it has a small folding scissors, a small knife, a tooth pick, tweezers, a nail file with a slotted screwdriver end, its also got a inch scale ruler printed on its long edge and its about as thick as two or three cards stacked on top of each other. I used to have a different one from another maker that had a 6" tape measure in one end.

    A few others if you like: For an average man (5'10") or woman (5'4"), one meter is very near the distance of your navel above the ground while standing barefoot (women are shorter than men, but have longer legs, so the navel is surprisingly stable). 150 centimeters is 5', or the distance from the ground to your mouth if male, to your eyes if female. An average man is 180 cm tall, and weighs the same, in pounds. An average woman weighs 125 lbs, so average humans, in groups, weigh close to 150 lbs. each. A heavily dressed man--with overcoat and gumboots, weighs 200 lbs. Ditto a normally dressed man, soaking wet. (in the US, add 10% to these numbers. Sorry)

    One cubit = 500 millimeters. Thus 300 cubits = 150 meters. Big boat. 30 meters = 100 ft. 30 centimeters = one foot (1.5% error).

    An American bill, whether one dollar or 100 dollars, weighs precisely 1 gram. As they wear they become dirty, maintaining almost precisely their initial weight (dope dealers count large amounts of cash by weighing it). A nickel weighs 5 grams. One dollar's worth of nickels weigh 100g, roughly one-quarer pound.

    A pint of water weighs a pound ("A pint's a pound the world around") 4% error.

    An average man, at a brisk marching pace, will have a stride very close to 32 inches (the Roman mile is derived from this = 1000 double paces = 5280 ft). A bit more relaxed pace and most can figure 30" exactly.

    An American football field, minus the end zones, is near an acre. Two American football fields side-by-side, now *including* the end zones = one hectare.

    All the above are slightly inaccurate, but are easy to measure, remember and intuit.

    2 replies

    An imperial pint may weigh 1.25 lbs. An American pint weighs 1.04375 lbs, at STD. Splitting hairs you may feel, but as Great Britain has gone metric (except for beer!), neither pints nor pounds are "official" there anymore, leaving the great preponderance of the pint unit to be in America, each weighing one pound. ;-)

    FWIW, the very definition of "fluid ounce" is that volume of water which weighs one ounce. 16 fluid ounces = 1 pint and 16 oz = 1 pound. It was all so simple back in the olden days

    Here in Mexico, we use the lenght between the fingers of a hand (forefinger and thumb) with one arm extended, to the figers of the other hand (you just have to stand like an Archer ready to throw an arrow, but instead of holding an arch, you hold tight the end of a rope, electric zip cord etc. and extend only one arm. The distance from the extended hand-arm to the other hand placed against your shoulder is almost exactly one meter! In that way you can very quickly measure a lenght of rope, cable etc. With a Little practice and checking, you can learn how to be precise to less than 1% error most times. Amclaussen.

    (sorry for my English description, English is not my native language).

    I carry around in my pocket a tiny tool set including a tape measure, slide caliper, fold up scissors etc Been so useful over the years I wouldn't go anywhere without it.

    Very interesting :) and good information to know. :) Love it!

    Also makes sense to measure your thumb to pinkie spread, the length of your shoe, and your arms tip to tip as far as you can spread them.

    Thank you for the helpful instruct able. Please make more.

    1 reply

    I have this small tape measure that hangs on to my key chain. I can measure anything up to 36" (yes, we in Canada still prefer the imperial system).


    4 years ago

    I added measurements on the inside of all of my belts and my wallet so all I need to do is take off my belt and I have an instant yard stick for smaller items my wallet works great

    1 reply

    Excellent. But (depending on what your waistline is doing) I think
    you will find that leather belts stretch over their lifetime, so it may
    be useful to check the linear precision of your calibration at regular

    And I have this thought . . . isn't it difficult trying to measure things when you're already having to use one hand to stop your trousers falling down ? ;-)