Size comparison · UK womenswear
What a UK 20 really measures across UK shops
The label says 20. The tape measure disagrees. We read each retailer’s own published chart — and at UK 20 the waist moves 7 cm between Roman Curve and Yours Clothing. That is most of a dress size, on the same number on the tag.
The quick answer
- Waist at UK 20: 98 cm (Yours) to 105 cm (Roman Curve) — a 7 cm spread.
- Bust: 113 cm (Yours) to 115.5 cm (Roman Curve).
- Hips: 122 cm (Yours) to 122 cm (Roman Curve).
UK 20 across five shops — the real numbers
Every figure below is read directly from each retailer’s published size guide, in centimetres.
| Retailer | Bust | Waist | Hips |
|---|---|---|---|
| Yours Clothing | 113 cm | 98 cm | 122 cm |
| Simply Be | 116 cm | 101 cm | 122 cm |
| Dorothy Perkins | 117 cm | 99 cm | 125 cm |
| Boohoo | 117 cm | 99 cm | 125 cm |
| Roman Curve | 115.5 cm | 105 cm | 122 cm |
Sources: yoursclothing.co.uk, roman.co.uk (Curve chart), dorothyperkins.com, simplybe.co.uk, read 24 October 2026.
Why the Roman gap doesn’t close as sizes go up
Most shops step up about 4 cm at the waist per size. Roman Curve also steps up about 4 cm — but it starts roughly a size ahead, so the gap narrows without ever disappearing:
| Size | Roman Curve waist | Yours / DP waist | Gap |
|---|---|---|---|
| UK 16 | 97 cm | 87 cm | 10 cm |
| UK 18 | 101 cm | 92–93 cm | 8.5 cm |
| UK 20 | 105 cm | 98–99 cm | 6.5 cm |
In practice: if your waist is 105 cm, Roman Curve at UK 20 is your closest fit — but at Yours or Dorothy Perkins you would be looking at a UK 22.
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UK 20 questions, answered
What are the measurements for a UK size 20 in cm and inches?
Across the UK curve retailers we checked, a UK 20 bust measures 113–117 cm (44.5–46.1 inches), a natural waist measures 98–105 cm (38.6–41.3 inches), and full hips measure 122–125 cm (48.0–49.2 inches). The waist varies by up to 7 cm on the same label.
Does a UK 20 fit the same at Yours Clothing and Roman Curve?
No. Yours Clothing publishes a UK 20 with a 98 cm (38.6 inch) waist and 122 cm hips. Roman Curve publishes a 105 cm (41.3 inch) waist and 122 cm hips — 7 cm more waist room. If your waist is 105 cm, Roman Curve at UK 20 fits you; at Yours you would look at a UK 22.
Which UK shop has the narrowest UK 20 waist?
Dorothy Perkins and Boohoo publish the same chart: a 99 cm (39.0 inch) waist at UK 20. Simply Be sits between them at 101 cm. Roman Curve is the widest at 105 cm.
Is a UK 20 the same across all UK shops?
No. Bust and hips are close across shops at UK 20 — within 4 cm and 3 cm — but the waist moves 7 cm. The label is a starting point, not a size.