The same garment, three different numbers
Buying clothing from a shop based in a different country almost always means meeting a size system that looks unfamiliar, even when the shop ships internationally and prices are shown in a currency you recognise. A UK 12 is not a US 12, and neither matches the EU number on a label from a shop based in continental Europe. None of this is an error on the label. It reflects three separate national sizing traditions that developed independently, and a voucher code covering the price of an order will not help if the garment itself does not fit, so getting the conversion right matters more than the discount.
A general size conversion
The tables below give a common, approximate conversion for women's and men's clothing sizes. They are a starting point, not a guarantee, because individual brands set their own measurements and can run smaller or larger than this general scale.
Women's clothing, approximate equivalents:
- UK 8 corresponds to EU 36 and US 4
- UK 10 corresponds to EU 38 and US 6
- UK 12 corresponds to EU 40 and US 8
- UK 14 corresponds to EU 42 and US 10
- UK 16 corresponds to EU 44 and US 12
- UK 18 corresponds to EU 46 and US 14
Men's clothing, approximate equivalents:
- UK/US small corresponds to EU 44 to 46
- UK/US medium corresponds to EU 48 to 50
- UK/US large corresponds to EU 52 to 54
- UK/US extra large corresponds to EU 56 to 58
These numbers are widely used as a general reference, but they are not a fixed standard the way a unit of measurement is. Two shops in the same country can label a very similar garment differently. Where a shop publishes its own size chart, usually with body measurements in centimetres or inches alongside the size label, that chart is the more reliable reference, because it reflects how that specific brand actually cuts its clothes rather than an industry average.
Why the systems differ in the first place
UK sizing developed from British tailoring standards, US sizing from a separate American system that has drifted over decades through what is often called vanity sizing, where the same body measurement gets labelled with a smaller number than it once did. EU sizing is closer to a standardised body measurement scale used across several European countries, which is part of why it tends to track more consistently between brands than UK or US numbering does. None of the three is more accurate than the others; they are simply different conventions applied to the same range of human bodies.
Measuring instead of guessing
When ordering from an unfamiliar brand, taking your own measurements, chest or bust, waist and hips in centimetres or inches, and comparing them against the shop's own size chart is more reliable than converting a size number you already know from a different market. This takes a few minutes and avoids the far longer process of arranging a return. It is particularly worth doing for fitted garments such as tailoring, denim or structured dresses, where a size or two out can change how a piece sits rather than just how loose it feels.
Children's sizing adds another layer
Children's clothing is generally sized by age or height rather than a number equivalent to adult sizing, and the ranges behind an age label, such as "4 to 5 years", can vary noticeably between brands because children of the same age differ more in size than adults do. Checking a height-based chart, where the shop provides one, tends to be more reliable than relying on the printed age alone.
Returns when the size is wrong
In the EU and the UK, distance selling rules generally allow a return within a set period after an online clothing order, whether or not anything is actually wrong with the item, subject to the goods being unworn and in resellable condition. In the US, there is no equivalent general federal right to return a correctly supplied item; return policies are set by the individual retailer, so the length of the return window and whether return shipping is free varies far more between US shops than it does across the EU or UK. Reading the specific return policy before ordering an unfamiliar size, rather than assuming a standard window applies everywhere, avoids an unpleasant surprise if a size guess turns out to be wrong.
Checking for a code once the size is settled
Once the right size is confirmed against a shop's own chart, it is worth checking whether a current voucher code or coupon code applies to the order before paying, since fashion retailers rotate promotions frequently. We check codes across 527 shops in 22 countries several times a day, and current listings for clothing and footwear retailers can be browsed under Fashion & Shoes for UK-based shops, or the matching US category for a US-based retailer.
Frequently asked questions
Is EU sizing more consistent than UK or US sizing?
It tends to track slightly more consistently between different brands, because it is closer to a standardised body-measurement scale, but it is still not identical across every EU-based retailer. A shop's own size chart remains the most reliable reference in any of the three systems.
Why does a US size sometimes feel smaller than expected?
Vanity sizing over recent decades has shifted US size numbers downward relative to actual body measurements, so a size that matches a UK or EU number on a conversion chart can still fit differently depending on how recently a brand last revised its sizing.
Should I size up when ordering from an unfamiliar brand?
Not automatically. Guessing up or down without checking the brand's own chart is no more reliable than guessing the original size. Comparing your own measurements to that specific chart gives a better result than adjusting a converted size by habit.
Do children's sizes convert the same way as adult sizes?
No. Children's clothing is usually labelled by age or height rather than a number equivalent to adult sizing, and the actual measurements behind an age label can vary between brands more than adult sizing does, so a height-based chart is usually the safer reference.
