What Is Sizing Like at Simply Be? An Honest Stylist's Guide

By Ella Blake – Senior Fashion Stylist & Founder | Tellar — Always honest, unbiased & unsponsored post

The short answer: Simply Be is broadly true to your usual UK dress size, but it isn't consistent across every category — tops and dresses tend to sit bang-on, denim is cut a touch neat, and swimwear, lingerie and shapewear reliably come up small. So if you've been told it "runs big" or "runs small," you're both right; it genuinely depends on what you're buying. After years of styling clients across the full size spectrum and pulling rail after rail of Simply Be for fittings, here's exactly how I'd approach it.

Where Simply Be fits true (and where it doesn't)

Simply Be specialises in sizes 10–32, and the fit logic shifts by department. Here's how it breaks down in real life:

Dresses & occasionwear – My most reliable category. Order your standard UK size; the cut is forgiving and the occasion range is genuinely lovely for fuller busts and hips.
Tops & blouses – True to size, though anything described as "relaxed" or "oversized" will be roomy, so size down if you want it neater.
Jeans & denim – Cut slightly trim. The Lift & Shape and Bootcut Stretch lines have built-in support panels that flatter curves beautifully, but I'd size up if you're between sizes or carry weight on the hips.
Swimwear, bras & shapewear – These come up small. Go up a size, and use your bust measurement rather than your dress size as your guide.
Coats & blazers – Winter coats have a relaxed, layering-friendly fit; tailored blazers are cut closer to the body. Don't assume one size covers both.
Footwear – A quiet hero. Wide and extra-wide options across heels, boots and trainers, plus up to five calf fittings on boots — a godsend if standard UK shapes never work for you.

A few honest fit notes from experience

Let me be straight with you, because that's the whole point of these posts. Simply Be quality can vary between their own-label pieces and the named brands they stock, and online reviews swing wildly — I've seen the same shopper call it "huge" and another swear it runs small in the same week. That's not user error; it's grading inconsistency across ranges, which most high street brands are guilty of these days.

My personal win: a pair of Lift & Shape bootcut jeans I pulled for a client who'd given up on denim entirely. We took her usual size, the internal panel did its job, and she actually teared up in the fitting room. My fail: years ago I ordered a swimsuit in my "normal" size for a shoot, didn't size up, and spent the day in something that fit like cling film. Lesson learned — and now I always tell people to treat swim and shapewear as their own separate sizing universe.

How to nail your Simply Be size first time

Always open the size guide on the individual product page — Simply Be grades by category, not by one universal chart.
Buy by your measurements, not your label size, especially for denim and swim.
If you're between sizes on structured pieces (blazers, fitted dresses), size up; you can always tailor the waist.
Order two sizes if you're unsure — returns are straightforward, and trying both at home beats guessing.

Best high street alternatives if Simply Be isn't quite right

If the fit or finish doesn't land for you, these are the brands I'd send a client to instead — chosen for genuinely inclusive sizing and dependable cuts:

New Look – The Curves range is trend-led, affordable and well-graded; my go-to for fashion pieces on a budget.
ASOS – ASOS Curve carries an enormous selection up to size 30, and own-brand styles are mostly true to size.
Marks & Spencer – The gold standard for consistent sizing, plus the best lingerie and shapewear on the high street.
Next – Reliably graded fits across a broad range; brilliant for workwear and wardrobe basics.
River Island – The Plus collection is bolder and more directional, cut a touch slim, so size with that in mind.
Monsoon – Beautiful occasionwear in extended sizes with a soft, fluid cut that skims rather than clings.
Seasalt Cornwall – Relaxed, comfortable everyday pieces with inclusive sizing and a gentle, forgiving fit.

Premium and designer options

Phase Eight – Premium occasion dressing up to size 22/24, with structured tailoring that flatters a fuller figure.
Hobbs – Polished workwear and event pieces with a grown-up, quietly elegant finish.
Me&Em – Clever, elongating designs and an extended size range built around real proportions.
Max Mara – The luxury end; look to its dedicated curve-focused sister line for sizing beyond the standard grade.

Two independent gems worth knowing

Lucy & Yak – A brilliant ethical independent doing colourful dungarees and easy separates in a properly inclusive size span, with a relaxed, comfortable cut.
Universal Standard – The size-inclusive pioneer running 00–40, with clean, modern staples graded so the fit stays true right across the range.

Never look at a size guide again

Tellar is the UK's leading sizing tool — your body matched to 1,500+ brands instantly, so you never squint at a confusing size chart again. Plus a Fashion Hub library of free posts covering every fashion query. Always honest, always unbiased, always free.

Measure once — using your bust, waist, hip, or an existing brand size you already trust.
Use the Store Size Lookup tool to get your precise size in any brand — COS, Reiss, Everlane, Arket and more.
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Get started at tellar.co.uk or jump straight to the Store Size Lookup tool.

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