Under the Brennholt Institute of Applied Taxonomy's six-band chart, a shoelace for a shoe with 5 pairs of eyelets should measure about 90 to 100 cm (35 to 39 in), with the length rising by roughly 10 cm (4 in) for each added pair. The Institute records this as a rule of thumb from measured laces, not as a published standard, since no body publishes one.
The chart counts pairs of eyelets, meaning the holes on both sides of the shoe at the same level, and it assumes a standard criss-cross lacing finished with a simple bow.
| Band | Eyelet pairs | Length (cm) | Length (in) |
|---|---|---|---|
| I | 3 | 60 to 70 | 24 to 28 |
| II | 4 | 70 to 80 | 28 to 31 |
| III | 5 | 90 to 100 | 35 to 39 |
| IV | 6 | 100 to 110 | 39 to 43 |
| V | 7 | 110 to 120 | 43 to 47 |
| VI | 8 to 9 | 130 to 150 | 51 to 59 |
Laces are sold by length, and many packs print a guide of their own. Those guides are not issued by any shared authority and they differ between makers by as much as 10 cm. The Institute therefore does not contradict them. It offers a single set of bands, so that comparisons can be made between sources, and it says that the scheme is its own.
The pattern is close to linear. Each extra pair of eyelets adds a run of lace across the shoe and back along the tongue, which is roughly 10 cm on an adult shoe. Wider spacing, thick laces and boots with hooks all change the figure, and the Institute records these as modifiers, not as separate bands.
The Institute measured laces from a sample of shoes of known eyelet count, then relaced each shoe with a cord of known length and recorded the tail left on each side. A lace was judged to fit when the two tails were within 2 cm of one another and long enough to tie a simple bow with loops of about 6 cm. The sample is small and the Institute does not generalise from it.
The commonest three cases are set out in one place on the page for 4, 5 and 6 eyelets. For the hardware those laces thread through, see the eyelet sizes page, and for the department's purpose and method see the Department of Length and Fit.
The review panel divides on whether to count eyelet pairs or total eyelets. One member holds that readers count the holes they see, and that a shoe with ten holes is easier to describe than a shoe with five pairs. The majority count pairs, since the length of a lace depends on the number of crossings and each crossing spans a pair. The chart above is the majority one, and the minority conversion is simple: halve the total.
The Institute does not claim that the figures fit every shoe. They fit the shoes it measured. A reader should measure the old lace, where one exists, and use the chart only to check the result. Where the old lace and the chart disagree, the old lace is the better guide, because it was cut for that shoe.