Shoe Size International Converter Formula
Understand the math behind the shoe size international converter. Each variable explained with a worked example.
Formulas Used
UK Size
uk_size = us_mens_size - 0.5EU Size
eu_size = us_mens_size + 33Foot Length (approx)
cm_length = us_mens_size * 0.847 + 17.145Variables
| Variable | Description | Default |
|---|---|---|
us_mens_size | US Men's Size | 10 |
How It Works
International Shoe Size Conversion
Shoe sizing systems differ by country. These conversions use standard industry formulas.
Formulas (Men)
UK = US - 0.5
EU = US + 33 (approximate)
Foot Length (cm) = US x 0.847 + 17.145
These are guidelines. Width varies significantly between brands and countries. European shoes tend to run narrower than American shoes.
Worked Example
Converting US men's size 10.
- 01UK = 10 - 0.5 = 9.5
- 02EU = 10 + 33 = 43
- 03Foot length = 10 x 0.847 + 17.145 = 25.6 cm
Frequently Asked Questions
How do women's sizes differ?
Women's US sizes are typically 1.5 sizes higher than men's for the same foot length. A men's 8 equals a women's 9.5.
Should I measure in cm?
Yes, measuring your foot in centimeters and comparing to the brand's cm chart is the most reliable method, especially for international purchases.
Do shoes from different brands fit the same?
No. Even at the same nominal size, width, arch support, and last shape vary significantly. Nike tends to run narrow, New Balance runs wide, and European brands often run small.
Ready to run the numbers?
Open Shoe Size International Converter