Simon Miller Size Guide: US to UK Conversion and Fit Notes

Simon Miller sizes most of its clothing in US letters from XS to XL and its tailored pants in US numbers from 0 to 14, and the brand marks most pieces true to size. Here is how that converts to UK sizing, with the exceptions. Shop by size in the Simon Miller collection at Coveti and the designer clothing edit.

Key facts

• Letter sizes: XS, S, M, L, XL
• Numeric sizes: US 0 to 14 on pants and some dresses
• Denim: waist sizes 25 to 32
• Most pieces: true to size, per the brand
• Runs small: the Beep Beep crochet mini; runs large: the Taja satin mini

Size conversion

This is Coveti’s guide based on standard US to UK conversion, not a brand chart. On Coveti, numeric pieces are shown in UK sizes (a US 4 is a UK 8) and letter pieces as the brand makes them.

Pieces that run differently

• Beep Beep crochet mini: the brand says it runs slightly small. Size up if you are between sizes, and if you want it to sit lower on the hips.
• Taja satin mini dress: the brand says it runs large. Consider sizing down if you are between sizes.
• Max belted cardigan: size up for a relaxed, oversized fit.
• Kini striped tee: true to size, size up for a boxier fit.

Fit by category

Model measurements

The brand lists its models on many product pages. A typical example: the model is 175cm (5 foot 9) and wears a size S, with a 32 inch bust, 24 inch waist and 36 inch hips. Use that as a reference point when choosing between sizes.

How to measure

Measure your bust at the fullest point, your natural waist and your hips at the widest point, then compare with the conversion above. If you are between sizes, pick the larger size for fitted pieces like the crochet minis and the smaller size in relaxed pieces like the knit cardigans.

Swimwear sizing

The Bwai bikini tops tie at the back and neck, and the bottoms are a low-rise French cut. Both are marked true to size. Shop the designer swimwear edit for more.

Frequently asked questions

Does Simon Miller run true to size?

Mostly yes. The brand marks almost every piece true to size, with a few named exceptions such as the Beep Beep skirt, which runs slightly small.

What UK size is a Simon Miller small?

As a guide, a Simon Miller S is a UK 8, an M a UK 10 to 12 and an L a UK 14.

Does Simon Miller use US sizing?

Yes. Letter sizes follow US conventions, and numeric pants and dresses are in US sizes 0 to 14.

Should I size up in the Beep Beep skirt?

The brand recommends sizing up if you are between sizes, and if you prefer it to sit lower on the hips.

Where can I find measurements for a specific piece?

Many Simon Miller product pages give the model’s height and size and a garment length; the Coveti product page shows the size note for each piece.

More Simon Miller guides

Every Simon Miller page by Coveti fashion editor Gemma Deeks: Who is Simon Miller?, Simon Miller dresses guide, Simon Miller skirts guide, Simon Miller tops and shirts, Simon Miller knitwear and knit sets, Simon Miller Fall 2026, Fringe skirts, Crochet dresses and skirts, Sequin mini dresses, Striped pants, Poplin shirts, Brands like Simon Miller. Shop every Simon Miller piece in stock.

Sources and method

Checked on 26 October 2026 by Gemma Deeks, fashion editor at Coveti. Fabric, care and fit notes are the brand’s own product page text; prices are Coveti’s live catalogue on that date and move with stock. Where a claim could not be checked it was left out, and where the page gives our own styling advice it says so.

• simonmillerusa.com, About us: lifestyle brand, Los Angeles studio, Chelsea Hansford as CEO and Creative Director
• simonmillerusa.com, Clothing: product pages with composition, care and the brand’s own sizing notes (332 pieces read on 26 October 2026, 199 full price pieces with a packshot carried by Coveti)
• Coveti live catalogue, 26 October 2026: prices and stock