What Is Sizing Like at ONLY Clothing?

By Ella Blake — Fashion Stylist | Tellar Fashion Hub — Always honest, unbiased & unsponsored

ONLY runs true to size for most pieces — but with one important caveat: their jeans and denim styles are where you really need to pay attention, because fit varies noticeably across their different cuts and leg shapes. In knitwear and tops, they're reliably consistent. In denim? It genuinely depends on which fit name you're buying.

About ONLY

ONLY is a Danish brand under the Bestseller group — the same umbrella that owns Vero Moda, Jack & Jones and Selected Femme. Founded in 1995, it's now one of the most widely stocked affordable fashion brands in Europe, available across the UK through ASOS, Next, and their own website. The aesthetic sits squarely in that casual-contemporary zone: good denim, easy knitwear, relaxed tailoring, and plenty of transitional pieces that work for everyday dressing without any fuss.

It's not a brand that's going to make front row at Fashion Week, but that's not the point. ONLY is the brand you go to when you want a great pair of straight-leg jeans for £35 that actually fit, or a cosy oversized jumper that doesn't bobble after two washes. For the price, the quality is genuinely solid, and the range is broad enough to have something for most people.

ONLY Size Guide

ONLY uses standard UK sizing across their range, broadly in line with EU sizing. Sizes typically run from a UK 6 to a UK 18 depending on the style. Here's how they translate:

ONLY / UKEUUSApprox. Bust (cm)Approx. Waist (cm)Approx. Hip (cm)UK 6 / XS34280–8362–6588–91UK 8 / S36484–8766–6992–95UK 10 / S-M38688–9170–7396–99UK 12 / M40892–9574–77100–103UK 14 / L421096–9978–81104–107UK 16 / XL4412100–10482–86108–112UK 18 / XXL4614105–10987–91113–117

Denim Fit Guide — This Is Where It Gets Important

ONLY's denim is their strongest category and also the one that confuses the most people, because each named fit is genuinely different. Here's a quick breakdown:

ONLALICIA / Straight leg: Their most popular and most forgiving fit. Runs true to size with a relaxed straight leg that suits most body shapes brilliantly. If you're new to ONLY, start here.
ONLBLUSH / Skinny: Runs slightly small — particularly through the hip and thigh. I'd suggest trying your usual size but being prepared to go up one if you're fuller in the hip.
ONLMOLLY / Wide leg: True to size at the waist. The wide leg is genuine and generous — great if you want proper wide-leg proportions, but bear in mind the leg opening is substantial.
ONLPOSH / Flare: True to size. The flare kicks out nicely from the knee — works especially well if you're 5'5" and above, as the flare hits at a good point.
ONLJAGGER / Mom fit: Runs a little large. Many reviewers (and I agree from experience) suggest sizing down one in this style. The relaxed cut gives it that authentic vintage mom-jean ease, but at your usual size it can look more shapeless than intended.

A note on leg lengths: ONLY offers three leg lengths in most denim styles — Short (30"), Regular (32") and Tall (34"). This is genuinely one of the brand's biggest strengths and something the high street doesn't always offer. If you're petite or tall, it makes a huge difference and I'd always recommend using it rather than rolling or hemming.

Fit by Garment Type

Knitwear & jumpers: Consistently true to size. ONLY knits tend to be slightly relaxed in cut anyway, so your usual size is reliably the right call. If you prefer a more oversized look, go up one — they layer brilliantly.
Blazers & tailoring: True to size with a slightly boxy, contemporary cut. If you're between sizes or have broader shoulders, size up. The shoulder seam placement really matters in their tailored pieces.
Dresses: Generally true to size, but check the fabric content. Jersey styles are forgiving; more structured or fitted styles (particularly bandeau or bodycon cuts) can run snug. Go up if in doubt.
Trousers (non-denim): True to size with a mid-rise that sits comfortably at the natural waist. Their wide-leg and straight-leg trousers in particular are very well cut and proportioned.
Tops & blouses: True to size. Very consistent across the range. Their ribbed tops do have stretch, so even if you're between sizes your usual will work fine.

My Honest Sizing Tips for ONLY

Use the fit name, not just "jeans". ONLY's denim fits are labelled and each one has its own sizing personality. Check the specific fit you're buying rather than assuming all their jeans run the same.
Use the inseam length options. This is one of the brand's best features — don't ignore it. The difference between a Regular and a Tall inseam is significant.
For in-between sizes, stick to your usual. Unlike some brands, ONLY doesn't skew dramatically small or large across most categories. Your typical UK size will generally land well.
Check the fabric composition. ONLY mixes cotton, stretch cotton and synthetic blends across their range. Higher stretch content means more give; 100% cotton pieces will have very little.

Similar Brands Worth Knowing About

If you love what ONLY does — that easy, affordable, Scandi-inflected everyday dressing — here's where else to shop across different budgets:

High Street:

Mango — ONLY's closest spiritual sibling on the high street. Similar aesthetic, slightly elevated fabrics, excellent denim and tailoring. A natural next step if you want to spend a little more.
H&M — Incredibly broad range at comparable prices. Particularly good for basics and seasonal trend pieces alongside ONLY's more consistent classics.
New Look — Strong denim offer at a similar price point. Their denim fit range has improved significantly and they're great for petite and tall options too.
River Island — More fashion-forward than ONLY but with a similar high street accessibility. Their denim and knitwear are perennially popular and well-reviewed.
Topshop — Now primarily online via ASOS. Still a go-to for trend-led denim and casualwear at accessible prices, with a strong denim heritage.
Next — Reliable, well-priced and excellent for basics and workwear alongside ONLY's casual focus. Particularly strong for tall and petite fits.
Great Plains — Quieter brand than the rest on this list, but genuinely brilliant for considered, wearable everyday dressing. Lovely fabrication and relaxed silhouettes with real longevity.
Boden — A step up in quality and price but worth knowing as an ONLY alternative for anyone wanting something a bit more durable and classic. Their denim and knitwear are excellent.

Premium Step-Up:

Whistles — The natural upgrade when you're ready to invest a bit more. Relaxed, intelligent dressing with better fabrics and more considered silhouettes.
Me&Em — Exceptionally well-cut British brand with a loyal following. Their wide-leg trousers and knitwear in particular are a genuine cut above.
Massimo Dutti — Zara's smarter sibling. Beautiful fabrication, understated styling and consistent sizing. Very much in the same spirit as ONLY but elevated considerably.

Two Independent Labels Worth Discovering:

Nobody's Child — A brilliant independent British brand with a strong sustainability focus and a genuinely lovely range of dresses, denim and knitwear. The aesthetic is feminine and relaxed, the prices are very accessible, and they've quietly become one of the most talked-about independent names in UK fashion. Highly recommended.
Lucy & Yak — If you love ONLY's relaxed, easy separates but want something with more personality, Lucy & Yak is your answer. Independent, ethical, sustainably made, and their dungarees and wide-leg trousers have a cult following for very good reason. Sizes are inclusive and the community around the brand is genuinely warm.

Get Your Exact Size at ONLY — and 1,500+ Other Brands

Denim sizing in particular is one of those areas where even the most experienced shoppers get caught out — different cuts, different stretch content, different rises. That's exactly the problem Tellar.co.uk was built to solve.

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