Finding the right shoelace length
Shoelace length depends on how many eyelet pairs your shoe has and how the lace crosses between them — more eyelets or a wider shoe both require longer laces.
The formula
This calculator models each crossing as the diagonal between eyelets using the Pythagorean theorem, Diagonal = √(Horizontal Spacing² + Vertical Spacing²), multiplied by the number of diagonal crosses in a standard criss-cross pattern (roughly 2 per eyelet pair after the first), then adds extra length at each end for tying a bow.
This is a geometric estimate based on typical eyelet spacing — actual shoes vary, and lacing style (criss-cross vs. straight bar) changes the math meaningfully, which is why both are offered. When in doubt, measure an existing lace that fits well, or round up to the next standard lace length. For general reference purposes only.