Size comparison · UK 18 to 32

UK 18 to 32 across five shops: the real measurements

Short answer: above UK 18 the labels stop meaning the same thing. At UK 20 the published bust runs from 113 cm at Yours to 117 cm at Boohoo and Dorothy Perkins — a 4 cm gap. At UK 28 it runs from 135.5 cm at Roman Curve to 141 cm at Boohoo. A woman measuring 141 cm is a UK 28 at Boohoo, a UK 30 at Yours and Simply Be, and a UK 32 at Roman Curve. Three different sizes, one body, one day.

Bust: the numbers at every size

Bust is where the spread is most consistent — roughly 4 to 5.5 cm at every size from 18 to 32. Read a row and you are looking at five garments with the same label that fit five different bodies.

Waist: where the gap is largest at the bottom, smallest at the top

Waist behaves the opposite way to bust. The spread is widest at UK 18 — 9 cm between Yours at 92 cm and Roman Curve at 101 cm — and narrows to just 3 cm by UK 24 and above. The reason is Roman Curve: it grades a much larger waist throughout, and the other four gradually catch up.

Hips: the chart nobody talks about

Hip measurements diverge least on the crown but most at the seam: Boohoo and Dorothy Perkins publish wider hips than everyone at every size. At UK 24 that is 137 cm against 130 cm at Roman Curve — 7 cm, or roughly two skirt sizes.

Sources, all read 24 October 2026: Yours Clothing, Roman (Curve range), Simply Be, Boohoo, Dorothy Perkins. Every figure is as published by the retailer. Nothing is interpolated, estimated or averaged.

The worked case: one body, three labels

Take a woman with a 141 cm bust, 123 cm waist and 149 cm hips.

Straightforward enough at that body. Now take a woman with a 141 cm bust and a 123 cm waist — the same bust but a narrower middle. At Boohoo she is a clean UK 28. At Roman Curve, the nearest bust match is UK 30, whose waist is 131 cm — 8 cm too loose. Roman's UK 28 has the right waist at 125 cm but a bust of 135.5 cm — 5.5 cm too small. She has no Roman Curve size that fits both. Every other shop gives her one.

Who goes furthest

If you have been sized out of a main-range chart, the practical question is who still sells your size.

Four of the five go to 32. Dorothy Perkins stops at 24 and publishes no larger chart at all — so a UK 26 there is not a fit problem, it is an unavailable product.

How to use these numbers

1. Measure once, in cm. Bust at the fullest point, waist at the narrowest, hips about 20 cm below the waist, tape level and not pulled tight.
2. Compare against the specific shop's chart, not your usual label. The tables above are the source; your habit is not.
3. Check which range the garment belongs to. Roman publishes a Main range (10–22) and a Curve range (16–32) with very different measurements. Buying Roman Curve in your Main-range size will run 10 cm loose on the waist.
4. Expect to be between sizes at the top of the range. A 5.5 cm bust spread at a size where grading steps are 6 cm means most people sit near a boundary.