THE SIZE TRANSLATOR

Will This Fit?

Stop guessing.

WhatSize translates clothing sizes across Nike, H&M, Zara, Adidas, Uniqlo, Gap, Levi's, and ASOS.

US, UK, EU, and Asian sizing • 649 variants • 100% offline

THE REAL COST OF GUESSING WRONG

You're in the checkout. £40 about to be spent. Zero idea if it'll fit.

Most people either waste £15 on return shipping, order two sizes and forget to return one, or just don't buy things they want.

We end that.

£15+
RETURN SHIPPING COSTS
Plus the hassle of repackaging, printing labels, going to the post office...
£0
JUST DON'T BUY THINGS YOU WANT
Because the anxiety of "will it fit?" is easier to avoid than deal with
£80
ORDER TWO SIZES, FORGET TO RETURN ONE
It's still in the bag under your bed, isn't it?
WhatSize costs less than one return and works forever.

HOW IT ACTUALLY WORKS

Your Closet Is Your Size Chart

That Nike hoodie you love? The Levi's that fit perfectly?

Every size you calculate gets saved automatically. Your personal reference library of what actually fits.

Your closet becomes your sizing Rosetta Stone.

Use It While You Shop

Standing in Uniqlo in Tokyo with no data connection? Browsing ASOS at midnight when you can't try things on?

We work 100% offline. Like a calculator. Or a flashlight.

Simple. Reliable. Always there when you need it.

(US, UK, EU, and Asian sizing • 649 variants)

Regional Variants Matter

Nike M in the US ≠ Nike M in Europe ≠ Nike M in Asia.

Most apps ignore this. They say "Nike M" and hope for the best.

We don't. We track 649 size variants across US, UK, EU, and Asian regions.

Because getting close isn't good enough when you're spending £50 on something you can't try on.

No Tracking. No Account. No BS.

Why isn't this free?

Because free apps sell your data, show you ads, try to upsell subscriptions, and disappear when VC funding runs out.

We charge £2.49 once. You own it forever.

Like buying a good tape measure instead of borrowing a broken one every time you need it.

CURRENTLY SUPPORTS

NIKE
ADIDAS
H&M
ZARA
UNIQLO
LEVI'S
GAP
ASOS

8 brands. 649 size variants across US, UK, EU, and Asian regions.

Why only 8 brands?

Because we only add brands where we have REAL data, not guesses.

Getting Nike wrong is worse than not having Nike at all.

Missing a brand?

REQUEST A BRAND →

Most requested brands get added first.

WhatSize app showing size conversion from Adidas Asia to Size M with waist 81-86cm

[ THREE STEPS.
NO PANIC. ]

Tell us what fits you now. We'll tell you what to buy next.

No measuring tape. No guessing. No returns.

  1. What Are You Shopping For?

    Select the brand and region you want to buy from.

    Example: "I want to buy from H&M UK"

  2. What Fits You Now?

    Tell us something you already own that fits perfectly. Or enter your measurements manually.

    Example: "I have a Nike M from the US"

  3. Get Your Size

    See your recommended size with the actual measurement comparison.

    Example: "H&M UK: Size L (chest: 102cm)"

Takes 30 seconds. No signup. No hassle.

[ ONE PRICE. NO TRICKS. ]

WhatSize

$2.99 USD

One-time purchase. Yours forever.

  • • 8 global brands (more coming)
  • • 649 regional size variants
  • • Works 100% offline
  • • No account needed
  • • No tracking or ads
  • • Free updates forever

Less than one return. Works forever.

QUICK
ANSWERS

WHAT IS WHATSIZE?

WHATSIZE IS A CLOTHING SIZE CONVERTER APP THAT INSTANTLY TRANSLATES YOUR SIZE ACROSS 9 GLOBAL BRANDS. IF YOU KNOW YOUR SIZE IN ONE BRAND, WHATSIZE TELLS YOU YOUR EXACT SIZE IN ANY OTHER BRAND - NO MEASURING REQUIRED.

HOW DOES IT WORK?

WHATSIZE USES OFFICIAL SIZE CHARTS DIRECTLY FROM BRAND WEBSITES. THE APP COMPARES BODY MEASUREMENTS LIKE CHEST, WAIST, HIPS, AND INSEAM ACROSS BRANDS TO RECOMMEND THE BEST-FITTING SIZE. ALL CALCULATIONS HAPPEN OFFLINE ON YOUR DEVICE.

DO I NEED TO MEASURE MYSELF?

NO. WHATSIZE WORKS BY CONVERTING BETWEEN BRANDS YOU ALREADY KNOW. IF YOU OWN A NIKE SHIRT IN SIZE LARGE, SIMPLY ENTER THAT INFORMATION AND WHATSIZE WILL TELL YOU WHAT SIZE TO BUY IN ZARA, H&M, OR ANY OTHER SUPPORTED BRAND.

WHY DO SIZES VARY BETWEEN BRANDS?

THERE ARE ZERO INTERNATIONAL SIZING STANDARDS FOR CLOTHING. EACH BRAND DEFINES THEIR OWN MEASUREMENTS FOR SIZES LIKE "MEDIUM" OR "SIZE 10." THE SAME SIZE LABEL CAN DIFFER BY 2-4 INCHES BETWEEN BRANDS.

OFFLINE MODE?

YES, 100%. WHATSIZE WORKS WITHOUT INTERNET. ALL DATA IS STORED LOCALLY ON YOUR DEVICE.

ACCOUNT NEEDED?

NO. IT'S COMPLETELY PRIVATE. NO SIGN-UP REQUIRED. YOUR DATA COLLECTION STAYS ON YOUR DEVICE AND NEVER LEAVES IT.

ONE-TIME PAYMENT?

YES. PAY ONCE, KEEP FOREVER. NO SUBSCRIPTIONS OR RECURRING CHARGES.

WHICH BRANDS?

9 BRANDS: NIKE, ADIDAS, H&M, ZARA, UNIQLO, LEVI'S, GAP, AND ASOS. MORE BRANDS COMING SOON.