French to UK Clothing Size Conversion

French sizes run higher than UK sizes, and the most commonly quoted pairing is FR 40 as UK 12. There is no single official chart, though, and published conversions disagree by a full size, so treat any conversion as a starting point and check the brand's own measurements.

If you run a store that sells across borders, this is a real fit problem. A shopper who guesses the wrong conversion orders the wrong size. AI size recommendation for fashion stores avoids the guess by matching body measurements to your own chart instead.

What is FR 40 in UK sizes?

Most conversion guides pair FR 40 with UK 12 and US 8. The Ma Grande Taille conversion guide gives that pairing for women's clothing.

Not every source agrees. French Entrée's size guide maps UK 12 to FR 38, which would put FR 40 at UK 14. Checked November 2026.

That gap is the main reason to avoid trusting one chart.

Why do French and UK sizes differ?

Each region built its own numbering. UK women's sizes are even numbers such as 8, 10 and 12. French sizes are also even numbers, but they start from a higher base, so the same body gets a larger number in France.

Brands also grade differently. Cut, fabric stretch and target customer all change what a "40" means. A fitted French blazer and a relaxed French knit can both be labeled 40 and fit differently.

How do you convert French sizes to UK step by step?

1. Find the brand's own size chart. Look for centimeter measurements of bust, waist and hips, not just a label.
2. Measure yourself. Use a soft tape on bare skin or thin clothing, and write down bust, waist and hips.
3. Match your measurements to the brand's ranges. The label that fits you is your size for that brand, whatever the conversion table says.
4. Use a conversion table only as a cross-check. If your measurements and the table disagree, trust the measurements.
5. If you fall between two sizes, read the fit notes. Choose the larger size for structured pieces and the smaller for stretch fabrics.

Is there a quick reference table?

This table shows one retailer's dress chart, so you can see how UK and European labels line up. It comes from the Primark women's size chart (checked November 2026), which lists UK and European sizes but no French column.

Size	UK	EUR
XS	6/8	34/36
S	10/12	38/40
M	12/14	40/42
L	14/16	42/44

Primark notes that actual measurements vary slightly by style. This is one example chart, so check your brand's own chart.

How do you read a French size label on a tag?

French women's labels are usually two-digit even numbers, often alongside a letter size such as S, M or L. If a tag shows both, treat the letter as the brand's rough guide and the number as the one to convert.

Look for other countries' sizes printed on the same tag. Many brands list several systems in a row, and using the printed pair beats any chart you find online. If the tag shows a UK size, use it.

What should you check besides the size number?

A converted number is only half the answer. Check these before you buy:

• Stretch. Knit and stretch fabrics forgive a size mismatch, while woven fabrics and tailored jackets do not.
• Cut. A slim cut can run small even in your usual size.
• Garment type. Dresses, trousers and tops can use different grading, so compare each garment's own chart.
• Reviews and fit notes. Look for lines such as "runs small".
• Return policy. If the conversion is a guess, a free exchange is your safety net.

A worked example: buying a French dress from a UK shop

Say your usual UK size is 12 and you want a French dress labeled 40. Start with the pairing most guides give (FR 40 as UK 12), then check the brand's measurements.

If the brand lists a bust range that includes your bust measurement, order the 40. If your bust sits at the top edge of the range, or the brand's notes say "fitted", look at the next size up. If the brand does not publish measurements, a full return window matters more than the conversion.

Where do UK and US sizes fit in?

UK and US labels also differ, which adds a second conversion. Our guide to UK to US women's size conversion covers that step.

Buying for children adds more trouble, because kids' sizes are often based on age or height. See kids clothing size conversion for that case.

How can stores stop shoppers guessing?

Stores selling in several countries can show the shopper's size in their own labels. With ZeDaq.ai, you enter your size chart in the Dashboard (or the Shopify app), and a 30-second body scan from one photo plus height recommends a size from that chart. If you have no chart for a garment type, it falls back to a generic UK/US/EU/AU chart.

Sizing questions also show up as returns. For a Nigerian example of the same mismatch problem, read Nigerian clothing sizes vs UK sizes.

FAQs

Is FR 38 the same as UK 10?

Often, yes, if you follow the FR 40 equals UK 12 pairing, because each step down is one French size and one UK size. Since sources disagree, confirm with the brand's measurements.

Are French and EU sizes the same?

No. French sizes are a national system, and EU labels vary by brand. Primark's chart, for example, lists European sizes separately from UK sizes.

Should I size up when buying French clothing?

Not by default. Compare your bust, waist and hips with the brand's chart, then use fit notes for stretch or structure.

Do French brands use the same sizes for every garment?

No. Tops, trousers and dresses often have separate charts, and cut changes the fit even when the label matches.