Question 1

What is my US size in EU?

Accepted Answer

According to the ISO 19407 standard, to convert US men's sizes to EU, first convert US men's to UK by subtracting 0.5, then convert UK to EU using the formula: EU = 1.27 × (UK + 23) + 2. For example, a US men's size 9 equals UK 8.5, which equals EU 43. For US women's sizes to EU, first subtract 2 to get UK size, then apply the same formula.

Question 2

How do UK and US shoe sizes differ?

Accepted Answer

UK sizes are approximately 0.5 size smaller than US men's sizes. For example, a US men's size 9 is roughly a UK size 8.5. For women, UK sizes are about 2 sizes smaller than US sizes. A US women's size 8 is approximately a UK size 6. This difference is due to the different measurement systems: UK sizes are based on the 'barleycorn' unit (⅓ inch or 8.46mm), while US sizes follow the same scale but with different starting points for men and women.

Question 3

Is shoe size conversion accurate?

Accepted Answer

Our shoe size converter uses the ISO 19407:2023 standard formulas, which provide the most accurate conversions between different sizing systems. However, even with the ISO standard, there can be variations between different shoe manufacturers. The standard notes that typical last length ranges are 13 to 25 mm over foot length for adults. For the best fit, we recommend measuring your foot in centimeters and using that as your reference point, as it's the most universal measurement.

Question 4

How do I measure my foot size accurately?

Accepted Answer

To measure your foot size accurately: Place a piece of paper against a wall, stand on the paper with your heel against the wall, mark the longest part of your foot, measure the distance from the wall to the mark in centimeters, and use this measurement to find your size in our converter. According to ISO 19407, adult shoe sizes are calculated from foot length in millimeters by adding an allowance of two shoe sizes. Measure both feet and use the larger measurement, as most people have one foot slightly larger than the other.

Question 5

What is the ISO 19407 standard?

Accepted Answer

ISO 19407:2023 'Footwear - Sizing - Conversion of sizing systems' is the international standard that provides the technical specifications for converting between different shoe sizing systems. The standard includes these key conversion formulas: EU shoe size = 1.27 × (UK shoe size + 23) + 2 and UK shoe size = (EU shoe size - 2) / 1.27 - 23. It also defines that foot length (L) in millimeters can be calculated from EU or UK sizes: L (mm) = (20/3) × (EU shoe size - 2) and L (mm) = (25.4/3) × (UK shoe size + 23). Our converter uses these ISO standard formulas to ensure accurate conversions.

Question 6

How do kids' shoe sizes work?

Accepted Answer

In the US, kids' shoe sizes start at 0 for newborns and typically go up to size 13.5, after which they transition to adult sizes starting at 1. The ISO 19407 standard applies the same conversion formulas to children's sizes, but with different starting points. Children's sizes are based on smaller foot measurements, with typical last length ranges of 6 mm over foot length for children. European kids' sizing follows the same numbering system as adults, just with smaller numbers (typically starting around EU 16 for infants).

US Men	UK	EU	Japan (cm)	Foot Length (cm)
6	5	39	24	24
6.5	5.5	39.5	24.5	24.5
7	6	40	25	25
7.5	6.5	40.5	25.5	25.5
8	7	41	26	26
8.5	7.5	42	26.5	26.5
9	8	42.5	27	27
9.5	8.5	43	27.5	27.5
10	9	44	28	28
10.5	9.5	44.5	28.5	28.5
11	10	45	29	29
11.5	10.5	45.5	29.5	29.5
12	11	46	30	30
13	12	47.5	31	31

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