WhatSize.Online started because we got tired of guessing our sizes when shopping abroad.
Living in the Netherlands, we'd often order clothes online from UK or US websites, or pick up items while traveling, only to find they didn't fit when we got home. We'd waste time hunting for size charts, trying to do mental math to convert measurements, and frequently end up returning clothes that didn't fit.
The only options we found were clunky size tables hidden on retailer websites or confusing charts that were impossible to use on a phone while shopping. We just wanted a quick answer to "What size am I in US sizing if I wear an EU 40?"
So we built the tool we needed ourselves - something simple that gives you the right size in seconds, whether you're at home or in a fitting room trying to figure out if that UK size 10 will actually fit you.
We want to make buying clothes internationally a no-brainer. We're working to:
Look, we know sizes are a mess. Every brand seems to have their own idea of what a "medium" is. Our converter gives you the standard size translations, but here's the reality:
Sizes can be all over the place because of:
We give you the standard conversion that works most of the time, saving you from getting lost in size chart hell when you just need a quick answer.
Tops, pants, dresses, shoes - men's and women's sizes all in one tool. No more switching between charts.
UK → US, EU → UK, or any other combo you need while shopping internationally.
We designed this for actual shopping trips, not just for sitting at your computer.
Dark mode for late-night shopping sessions when you should probably be sleeping.
Browsing American websites as a Brit? UK women's sizes are typically 4 sizes larger than US (a UK 14 = US 10). Men's clothing often uses the same numbers but with totally different measurements behind them.
European sizing is its own world. A women's EU 40 is roughly a UK 12. Men's shirts in EU sizes often use centimeters for chest measurement while UK uses inches. We sort all that out for you.
Shoe sizes are the worst. A US men's 10 is about a UK 9 and EU 44. For women, a US 8 is around a UK 6 and EU 39. Our tool handles the math so you don't have to.
Is an XL the same as a size 16? Depends who you ask. We translate between letter sizes (S/M/L) and number sizes to clear up the confusion.