Additional Math Pages & Resources

Tuesday, January 26, 2010

How long should they be?

We're talking shoelaces today. How long should shoelaces be? We want them easy to tie but not so long that they drag on the ground, or you trip on them.

Several years ago I discovered the Ultimate Shoelace Website. Ian Fieggen, who created the site, has hosted more than 10 million visitors and can tell us almost everything we need to know about shoelaces. Except two things:

(1) Which shoes we are wearing today, and (2) the pattern of the laces through the shoes.

Here is his advice on selecting the length of shoelaces.

The length of a shoelace depends on five key factors:
  1. Lacing Method. The diagram shows uses Criss Cross Lacing.
  2. [P] - Pairs of Eyelets. The diagram has 6 pairs of eyelets (12 eyelets total).
  3. [H] - Horizontal spacing between centres of adjacent eyelets, measured with the shoe tight on the foot.
  4. [V] - Vertical spacing between centres of eyelets, or from the top of one eyelet to the top of the next eyelet.
  5. [L] - Length of each shoelace end (with which you tie your knots), measured from the middle of the knot to the end of the lace. About 250 mm (10") is about right.
The length of the lace should be (H + square root of (H squared + V squared) x (P-1)+L) x 2.

We don't do squares and square roots in Excel Math. That's algebra. So you could just put your numbers into his online shoelace length calculation engine: HERE

Or alternatively, measure your old laces.

If you don't have any, or your old ones broke, you can use a thin piece of string to lace up your shoes, then pull out the string, measure it, and go buy that size shoelaces.

If your shoelaces come undone all the time, you might be tying a granny knot. Here's the page for you.

On his page, Ian says teachers spend lots of time tying shoes. My wife is a PE teacher and she confirms his statement. Maybe a couple dozen pairs a day (in addition to her own).


Ian has written a book called Laces, and he included a sample pair of laces on the cover so you can practice!

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