Shoelace Length Calculator (criss-cross & straight bar, from eyelet pairs)

Understanding the shoelace length calculator — concept and principle

This calculator works out how long a shoelace needs to be from the number of eyelet pairs, the gap across the tongue, the spacing between eyelets, the lacing style and the length of the bow ends. Use it when replacing laces or changing to a different lacing pattern.

Criss-cross path + ends: with the default inputs the result is 107 cm lace (≈ 42.2 in).

How it is calculated

With k eyelet pairs, w across the tongue and v between neighbouring eyelets:

Criss-cross path = w + 2 × (k − 1) × √(w² + v²).
Straight bar path = k × w + 2 × (k − 1) × v.
Total lace = path + 2 × bow-end length.
Inches = cm ÷ 2.54.

The principle

A lacing pattern is a path through two columns of holes. In criss-cross lacing, after a horizontal segment at the bottom, every segment runs diagonally to the opposite side and one hole up, so each one is the hypotenuse of a right triangle with sides w and v. In straight bar lacing, every pair has a horizontal bar on top, while underneath each end climbs up its own side. Adding the two loose ends needed to tie a bow gives the total length. Criss-cross uses more lace because diagonals are longer than vertical steps.

Worked example

Default inputs: 6 eyelet pairs, 5 cm across, 1.5 cm between eyelets, criss-cross, 25 cm ends.

Diagonal = √(5² + 1.5²) = 5.220 cm.
Criss-cross path = 5 + 2 × 5 × 5.220 = 57.2 cm.
Straight bar path (for comparison) = 6 × 5 + 2 × 5 × 1.5 = 45 cm.
Ends = 2 × 25 = 50 cm; total = 57.2 + 50 = 107 cm (42.2 in).

Each point is the calculator re-run with only “Gap between the two eyelet rows (cm)” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

Gap between the two eyelet rows (cm)	Lace length needed (cm)
1.25	71
2.5	82
3.75	94
5	107
6.25	121
7.5	134
10	161

How to read the result

Laces are sold in standard lengths; round up to the next size. A thicker lace and tighter pulling use slightly more length. If your current laces are too long, switching to bar lacing shortens what you need.

Common mistakes

Counting all eyelets instead of pairs.
Measuring the gap with the shoe untied and spread open.
Forgetting length for the bow.
Assuming the same lace fits all lacing styles.

Keep in mind: The result is an estimate; lace thickness and tension change it by a few centimetres.

Frequently asked questions

What length laces for 6 eyelet pairs?

About 107 cm for criss-cross lacing with 25 cm bow ends.

Which lacing uses less lace?

Straight bar lacing, because it has no long diagonals.

How do I measure the gap across the tongue?

Measure between the eyelet rows with the shoe laced and worn normally.

Sources: Geometry of the lacing path (Pythagorean theorem for the diagonal segments), any geometry textbook

Checked 9 Nov 2026. Geometry of the lacing path (Pythagorean theorem for the diagonal segments); the bow-end length is an example value you can change. 1 in = 2.54 cm exactly (international inch, 1959).

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