Free Shoe Size Converter | US, UK, EU & Japan Sizes

Find your true shoe size in US, UK, EU, and Japanese sizing — in seconds.

Shoe size charts disagree with each other constantly, and that’s because they were never measuring the same thing. This converter skips the confusion: it works from the one measurement that never lies — the length of your foot — and translates it into every major sizing system. Measure once, shop anywhere in the world with confidence.

Convert Your Size

Your size in women’s sizing, based on a cm foot:

US
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UK
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EU
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JP
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Tip: if you fall between two rows, always go with the larger size — a little room beats a pinched toe every time.

How to Measure Your Feet Correctly

A converter is only as good as the number you feed it. Most women are wearing the wrong size because they were measured once — at age sixteen. Here's how to do it right, at home, in two minutes:

  1. Measure in the evening. Feet swell slightly during the day, so an evening measurement reflects your feet at their largest — the size your shoes need to fit.
  2. Stand on paper, full weight. Place a sheet of paper on a hard floor against a wall. Stand on it with your heel touching the wall, wearing the socks you'd normally wear with the shoes you're buying.
  3. Mark the longest toe. Mark where your longest toe ends (it's often the second toe, not the big one). Measure from the wall edge of the paper to the mark, in centimeters or inches.
  4. Measure both feet. Almost everyone's feet differ slightly. Use the larger foot's measurement — it's the one your shoes need to fit.

Why Shoe Size Charts Disagree With Each Other

If you've ever been a US 8 in one brand and a US 9 in another, you haven't imagined it. Here's what's going on:

  • Different units entirely. US and UK sizes are based on the barleycorn — an old unit equal to one-third of an inch. EU sizes are based on the Paris point (two-thirds of a centimeter). Japanese sizes are simply foot length in centimeters. They're three different rulers that only roughly line up.
  • Every brand's "last" is different. A last is the foot-shaped form a shoe is built on. Brands design their own, so two shoes labeled the same size can fit differently. This is why converting from your foot length beats trusting any single brand's chart.
  • Vanity sizing exists in shoes too. Some brands quietly cut their shoes larger so customers feel good about "being" a smaller size. Your foot length doesn't flatter anyone — which is exactly why it's trustworthy.

What Changes After 40

This is the part nobody told us, and it matters more than any conversion chart:

  • Feet get longer and wider. Over the years, ligaments loosen and arches settle, so feet tend to spread. Many women go up half a size — sometimes a full size — between 40 and 60 without realizing it.
  • The fat pad thins. The natural cushioning under the ball of your foot gets thinner with age, which is why shoes that were comfortable at 30 can feel harsh at 50. Cushioning and arch support start mattering more than style alone.
  • Re-measure once a year. It takes two minutes (see above), and it ends the cycle of blaming your feet for what is actually just the wrong size. If your long-trusted size has started pinching, don't suffer — measure. And it's not just feet that change — most women are wearing the wrong bra size too.

A Note on Width

If your feet feel tight across the toes but the length is right, don't just size up — a longer shoe on a narrow foot slides at the heel and creases oddly. Look for the same length in a wide width (marked W, or D for some brands) instead. Width is a separate measurement from length, and most quality brands offer it.

Frequently Asked Questions

Is a women's size 8 the same as a men's size 8?

No — they're 1.5 sizes apart. A women's US 8 is roughly a men's US 6.5. The converter handles that automatically when you switch between women's and men's sizing.

What is my EU size if I'm a US 8?

Around EU 39 — but don't convert size-to-size. Convert from your foot length instead, because a "US 8" already varies between brands. That's the whole point of the tool.

Should I buy running shoes in my measured size?

Go half a size up from your measured size for running or long walks. Feet swell with activity and toes need room to splay on impact — black toenails are almost always a too-small shoe, not a running problem.

My two feet measure different sizes. Which do I use?

Always the larger foot. Shoes are sold in pairs, and the smaller foot adapts far more comfortably than the larger one suffers.

Should I measure with socks on or off?

With the socks on — specifically, the socks (or tights) you'll actually wear with the shoes you're buying. A winter boot measured in bare feet will lie to you.

Do feet really keep changing after 40?

Yes. Ligaments loosen, arches settle, and feet gradually get longer and wider through midlife and beyond. It's normal, it's not your fault, and a yearly two-minute re-measure keeps your shoes honest.

The Bottom Line

Stop trusting the number stamped inside your old shoes — trust the tape measure instead. Two minutes tonight, and every pair you buy from here on fits the feet you actually have. And since change doesn't stop at your feet after 40: know your waist-to-hip ratio next. Small numbers, big confidence.

More Free Tools from LaVestia

One good measurement deserves another. Try the rest of the Size & Fit Assistant:

Your privacy: the converter runs entirely in your browser. The number you type is never sent anywhere, never stored, and never seen by anyone — not even me. Close the page and it's gone, exactly as it should be.