Climbing shoes are meant to fit snugly, and many climbers wear them one to two sizes smaller than their street shoes. That makes sizing tricky: too small and you cannot climb for more than a few minutes; too large and your foot slips on small holds. This calculator uses the sizing advice published by Black Diamond and Scarpa to suggest the size to try from your foot length and the kind of fit you want.
How to use the climbing shoe size calculator
- Measure your longer foot, heel to longest toe.
- Enter the length in centimetres, millimetres or inches.
- Choose the fit: highest performance, all-day performance or all-day comfort.
- Read the size to try in EU and US, plus the range Scarpa gives for most people.
Climbing shoe size formula
climbing size = street size − 2 (highest performance) / − 1 (all-day performance) / − 0.5 (all-day comfort)
Scarpa: downsize ½ to 1 full size for most people, up to 2
The table and rules are from Black Diamond’s sizing guide as published by the retailer Bivouac, and Scarpa’s advice from the same retailer’s page (retrieved 2026-10-15). A European size is 6.6 mm of length, so two sizes is 1.3 cm. Black Diamond’s plus signs (4.5+) mark the sizes between whole US numbers.
| EU | US men’s | US women’s | Foot measurement (cm) |
|---|---|---|---|
| 35.5 | 4 | 5 | 22.05 |
| 36 | 4.5 | 5.5 | 22.38 |
| 36.5 | 4.5+ | 5.5+ | 22.71 |
| 37 | 5 | 6 | 23.04 |
| 37.5 | 5.5 | 6.5 | 23.37 |
| 38 | 6 | 7 | 23.7 |
| 38.5 | 6.5 | 7.5 | 24.03 |
| 39 | 6.5+ | 7.5+ | 24.36 |
| 39.5 | 7 | 8 | 24.69 |
| 40 | 7.5 | 8.5 | 25.02 |
| 40.5 | 8 | 9 | 25.35 |
| 41 | 8.5 | 9.5 | 25.68 |
| 41.5 | 8.5+ | 9.5+ | 26.01 |
| 42 | 9 | 10 | 26.34 |
| 42.5 | 9.5 | 10.5 | 26.67 |
| 43 | 10 | 11 | 27 |
| 43.5 | 10.5 | 11.5 | 27.33 |
| 44 | 10.5+ | 11.5+ | 27.66 |
| 44.5 | 11 | 12 | 27.99 |
| 45 | 11.5 | 12.5 | 28.32 |
| 45.5 | 12 | 13 | 28.65 |
| 46 | 12.5 | 13.5 | 28.98 |
| 46.5 | 12.5+ | 13.5+ | 29.31 |
| 47 | 13 | 14 | 29.64 |
Worked example
A climber’s longer foot is 26 cm and wants an all-day performance fit.
- 26 cm falls at the 26.01 cm row of the table, EU 41.5, the street size.
- All-day performance subtracts one EU size: EU 40.5, US men’s 8, US women’s 9.
- Scarpa’s range for most people: EU 40.5 to 41.
Fitting climbing shoes
- Snug, not painful: toes should touch the end but not be crushed for the all-day fits.
- Heel: should not lift when you pull the toe up.
- Stretch: leather stretches more than synthetics, so it can be sized tighter.
- Different models fit differently, even from one maker.
The size is a starting point and not a guarantee, and shoes should be tried on. For ordinary shoes use the Shoe Size Calculator (foot length); for running the Running Shoe Size Calculator. This page is general guidance.
Sources
Every figure above comes from these pages, read directly on the dates shown. Brand names are used only to identify published charts.
- Bivouac — Black Diamond rock climbing shoe size guide (size table and fit rules) — checked 2026-10-15
- Bivouac — Scarpa rock climbing shoes size guide (downsize ½ to 1, up to 2) — checked 2026-10-15
Frequently asked questions
How much smaller should climbing shoes be?
Black Diamond says its climbing shoes are sized on the actual last, so you take a smaller size than your street shoe: subtract 2 EU sizes for the highest performance fit, 1 for all-day performance and 0 to ½ for all-day comfort. Scarpa says most people downsize ½ to 1 full size and some up to 2.
Why do climbing shoes run small?
Street shoes have space built in for comfort; climbing shoes are made to the dimensions of the last so the foot is held snugly for the best connection to the rock.
Do all brands size the same?
No. Models and brands differ, and some makers advise little or no downsizing. These rules are from Black Diamond and Scarpa only; check the brand’s guide for the shoe you want.
What is a Brannock measure?
Black Diamond’s rule starts from the measurement of your foot on a Brannock device, which is the street size. The calculator estimates that from your foot length with the Black Diamond table.
Should I try them on?
Yes, climbing shoes must be tried on or returned if they do not work. The Shoe Size Calculator (foot length) gives your street size for comparison.