What Is Sizing Like at Fabletics? An Honest Stylist's Fit Guide

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

The short answer: Fabletics runs broadly true to size, so most of the time you can take your normal UK size and trust it. The catch is that "true to size" means something specific in activewear — it's measured against a snug, body-hugging fit, not the relaxed cut you'd get from a jumper. So if you're someone who likes a bit of breathing room, you'll feel that compression more than you might expect. Below I'll walk you through exactly how their leggings, bras and tops fit, where the sizing can trip you up, and which brands I'd send you to depending on your budget.

How Fabletics Actually Fits

Fabletics is the Kate Hudson-backed activewear label that sells through a VIP membership model — worth knowing because it shapes the whole experience, but it doesn't change the fit. What changes the fit is the fabric, and this is the bit most people miss. Fabletics builds the same leggings in different compression weights, and each one sits on your body differently:

PowerHold – their firmest, most compressive fabric. Genuinely holds you in, brilliant for HIIT, weights and running. It fits snug by design, so this is the one where you'll feel it most.
PureLuxe – light compression, that buttery-soft hand-feel. Lovely for yoga, pilates and lounging, but far more forgiving and relaxed on the body.
Motion365 – sits in the middle. A safe all-rounder if you're not sure where you land.

My honest steer: if you're between two sizes in a PowerHold style, size up rather than down. The compression does the holding-in work for you, and going too small is where leggings turn sheer across the bottom and dig in at the waistband. I learned this the hard way years ago — I ordered a pair of compression leggings a size down "to be safe," wore them to a reformer class, and spent the whole hour tugging the waistband up and praying nobody was behind me in the squat. Never again. With compression wear, comfortable beats heroic every single time.

Leggings, Bras and Tops — The Detail

Leggings: sized XXS to 4X (roughly a UK 4–32). The big win is the inseam choice — Short, Regular and Tall — so petite and taller women can finally get the length right rather than rolling or bunching. Measure your waist and hips against the on-page chart and go from there.
Sports bras: also XXS to 4X, but with proper cup sizing and three support levels — light, medium and high. Don't guess here. Match support to the activity: high for running, light for yoga.
Tops & clothing: generally S to 4XL and pretty reliable to size. A touch more relaxed than the leggings.

One styling note from experience: lighter colours and pastels can read slightly sheer when you bend or squat, especially in the more compressive fabrics. If you live in the gym mirror's eyeline, go for darker shades or a print — they're far more forgiving and you'll never think about it again.

Where to Shop if Fabletics Isn't Quite Right

If the membership model puts you off, or the fit isn't landing, here's where I'd send clients by budget.

High Street

M&S – the Goodmove range is genuinely underrated: supportive, well-priced and consistent sizing season to season.
Next – its Active line is great for everyday gym staples without the price tag, and the size charts are dependable.
H&M – the Move collection is your budget-friendly entry point; perfect for trying a trend before committing.
Gap – GapFit basics are soft, simple and brilliant for low-impact days and lounging.
Superdry – its Sport range leans sporty-casual, ideal if you want pieces that work outside the gym too.
Calvin Klein – the perfect crossover for elevated loungewear and athleisure that doesn't shout "workout."

Premium

Sweaty Betty – the British benchmark for premium activewear. Flattering, technical and built to last; my go-to for clients who want one perfect pair.
Lululemon – still the gold standard for technical leggings. The fit is precise, so check their chart carefully and don't assume your high-street size.
Gymshark – gym-focused, fashion-led and well-priced for the quality. Excellent for serious training kit.

Luxury / Designer

Max Mara – its Leisure line brings genuine luxury to athleisure: beautiful fabrics and considered cuts for off-duty polish.

Two Independents Worth Knowing

TALA – the sustainability-led British label founded by Grace Beverley. Sculpting fabrics, sharp design and a cult following for good reason.
Adanola – the Manchester-born independent that's quietly become the it-brand for minimalist activewear and elevated everyday sets.

The Tellar Shortcut

Honestly, the simplest way to skip all the guesswork is to let the numbers do it for you. That's exactly why I built Tellar — the UK's leading sizing tool. You measure once (bust, waist, hip, or just enter your size in a brand you already know), and Tellar instantly matches your body to 1,500-plus brands. No more squinting at size guides, no more returns roulette.

Measure once using bust, waist, hip — or an existing brand size you 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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Start here: https://tellar.co.uk/Store Size Lookup: https://tellar.co.uk/store-size-lookup/

And once you've sorted your size, dive into the Tellar Fashion Hub — a library stacked with free posts from our top stylists. Honest. Unbiased. Independent. Always free. Style advice, top picks and the best brands, all in one place.

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