Reference Tool · Free
Safety Boot Size Guide
Convert safety footwear sizing across US, UK, EU, China and Japan — plus width fittings for ASTM F2413 and EN ISO 20345 boots.
Size converter
Matching sizes for foot length 280 mm
mm
280
US M
10
US W
11.5
UK
9
EU
44
CN
44
JP
28.0
How to measure your feet
Foot length in millimetres is the most accurate measurement for safety footwear. Take 5 minutes to do it properly and you will avoid the 40% of online boot returns caused by size mismatch.
- 1
Measure at the end of the day
Feet swell throughout a shift — measuring in the evening or after several hours on your feet captures the maximum size and prevents cramped boots.
- 2
Wear your work socks
Thick thermal or cushioned safety socks add 2–3 mm of length. Always measure with the socks you plan to wear with the boots.
- 3
Stand on a sheet of paper
Place a sheet against a wall. Stand with your heel touching the wall and your weight evenly distributed — sitting under-measures by 3–5 mm.
- 4
Mark the longest toe
With a pencil held vertically, mark the paper at the tip of your longest toe. Do both feet — one foot is usually 2–4 mm longer.
- 5
Measure to the wall
Measure the distance from the wall edge to your mark in millimetres. Always buy for the longer foot.
- 6
Add 10 mm of toe room
Safety boots with steel or composite toe caps need 10 mm (about 1 cm) of room in front of your longest toe so the toe cap never presses on your nails when you walk downhill.
US to EU safety boot size conversion chart
Cross-reference table for safety-footwear sizing across the major systems. Sizes are based on Brannock / ISO 9407 foot-length measurement.
| Foot length | US Men's | US Women's | UK | EU | China | Japan |
|---|---|---|---|---|---|---|
| 230 mm | 5 | 6.5 | 4 | 38 | 38 | 23.0 |
| 235 mm | 5.5 | 7 | 4.5 | 38.5 | 38.5 | 23.5 |
| 240 mm | 6 | 7.5 | 5 | 39 | 39 | 24.0 |
| 245 mm | 6.5 | 8 | 5.5 | 39.5 | 39.5 | 24.5 |
| 250 mm | 7 | 8.5 | 6 | 40 | 40 | 25.0 |
| 255 mm | 7.5 | 9 | 6.5 | 40.5 | 40.5 | 25.5 |
| 260 mm | 8 | 9.5 | 7 | 41 | 41 | 26.0 |
| 265 mm | 8.5 | 10 | 7.5 | 42 | 42 | 26.5 |
| 270 mm | 9 | 10.5 | 8 | 42.5 | 42.5 | 27.0 |
| 275 mm | 9.5 | 11 | 8.5 | 43 | 43 | 27.5 |
| 280 mm | 10 | 11.5 | 9 | 44 | 44 | 28.0 |
| 285 mm | 10.5 | 12 | 9.5 | 44.5 | 44.5 | 28.5 |
| 290 mm | 11 | 12.5 | 10 | 45 | 45 | 29.0 |
| 295 mm | 11.5 | 13 | 10.5 | 45.5 | 45.5 | 29.5 |
| 300 mm | 12 | 13.5 | 11 | 46 | 46 | 30.0 |
| 310 mm | 13 | — | 12 | 47 | 47 | 31.0 |
| 320 mm | 14 | — | 13 | 48 | 48 | 32.0 |
| 330 mm | 15 | — | 14 | 49 | 49 | 33.0 |
Width fittings explained
Safety footwear width is measured across the ball of the foot. US systems use letter codes (D, E, 2E, 4E), European systems use F/G/H/K. Both ASTM F2413 and EN ISO 20345 permit these variants.
| Width | US label | EU label | Typical use |
|---|---|---|---|
| B / Narrow | B (women) / AA (men) | — | Narrower instep and ball, common for smaller frames. |
| D / Medium | D | F (medium) | Standard width — fits most workers. |
| E / Wide | E, 2E | G (wide) | Extra room across the ball of the foot. |
| 2E / EE | 2E, EE | H | Wide fit used for work boots with thick socks. |
| 4E / EEEE | 4E, EEEE | K | Very wide fit — orthopaedic or swelling accommodation. |
| 6E | 6E | — | Rare US-only extra-wide fit; select brands only. |
Break-in and on-site fit check
First 40 hours
Expect light pressure at the heel and instep — this resolves as the leather conforms. Sharp pain or toe-cap contact means wrong size.
Toe test
Kick a flat wall lightly. Your longest toe should never feel the toe cap — if it does, the boot is too short regardless of labelled size.
Heel lock test
With boots laced, walk on tiptoes. A properly fitted boot keeps your heel anchored within 2–3 mm of the insole.
Frequently asked questions
How do I convert US shoe size to EU for safety boots?
US men's 10 = EU 44, US men's 9 = EU 42.5, US men's 8 = EU 41. For exact conversions across half sizes and women's sizing, use the size chart above — it is based on foot length in millimetres, the definitive measurement.
Are safety boots sized differently from regular shoes?
Yes. Safety boots with steel or composite toe caps often feel 3–5 mm shorter than the equivalent casual shoe because the rigid cap reduces toe-box flex. Most safety-footwear brands recommend ordering your true measured size and allowing 10 mm of toe clearance.
What width fitting should I order?
Order "D / Medium" (US) or "F" (EU) as a default — most brands assume this fit. Order "2E", "4E" or "G / H" (EU wide) if you have a high instep, wear thick socks, or experience numbness in standard boots.
Do I order my street-shoe size in steel-toe boots?
Generally yes, but with two adjustments: (1) account for work-sock thickness by rounding up if between sizes, and (2) confirm 10 mm of toe-to-cap clearance after lacing.
How do I know if my safety boots fit correctly?
Correct fit: the heel does not slip when walking, you can wiggle your toes freely, the toe cap never touches your toes (including when walking downhill), and the laces do not need to be overtightened to hold the heel. Break-in discomfort is normal but should resolve within the first 40 hours of wear.
Can I return safety boots that do not fit?
Policies vary. Most safety-footwear retailers accept returns within 30 days if the boots have only been worn indoors on clean surfaces. Check the return policy before opening the box outdoors or on site.
Ready to choose your boots?
Once you know your size, learn what the certification labels mean with the Compliance Label Decoder, or read the full construction safety footwear guide covering ASTM F2413 and EN ISO 20345.