What Is Sizing Like at Sisley?

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

Sisley runs small — and I mean genuinely small. As an Italian brand under the Benetton Group umbrella, it sizes in EU measurements, and in my experience (and that of virtually every client I've pointed towards their gorgeous tailoring) you will almost certainly need to go up one size, sometimes two, compared to your usual UK size.

I remember styling a client a few years back who was a solid UK 12 everywhere else — Zara, Reiss, you name it. She fell in love with a Sisley blazer in a deep rust colour and ordered her usual size. It arrived and she could barely get her arms into it. Once we sized up to a 44 EU (UK 14 equivalent), it was perfect. That's Sisley in a nutshell: beautiful, well-made clothes that will fit you brilliantly — once you've cracked the sizing code.

The Italian Sizing Factor — What It Actually Means for You

Sisley is, at its heart, a European brand with a distinctly Italian sensibility. Italian fashion sizing runs notably smaller than UK sizing across the board, and Sisley is no exception. The brand's clothes are cut with a Continental silhouette in mind — generally narrower across the shoulders, slimmer through the torso, and with less allowance in the hip than British and American sizing tends to offer.

What this means in practice:

If you're a UK 10, start with an EU 40 (which sounds like it should be a UK 14, but in Sisley's world maps much closer to a 10–12).
If you're between sizes, always size up — Sisley's fabrics are generally not very forgiving, particularly in their tailoring and fitted knitwear.
If you're broader across the shoulders or fuller in the chest, go up two sizes and check the measurements carefully. Their blazers and structured jackets are particularly snug across the back.

The one exception I'd give to this rule is their jersey pieces — softer T-shirts, draped tops and stretch fabrics. These tend to have more give and you might find your usual UK size works fine. But for anything structured, go up, always.

Sisley Size Conversion Table

Sisley uses EU sizing as standard. Here's how that maps to UK and US sizes, along with approximate body measurements to help you find your fit:

EU SizeUK SizeUS SizeBust (cm)Waist (cm)Hips (cm)34628062873684846691381068870954012892749942141096781034416121008210746181410486111

Important note: treat these as a starting guide, not gospel. Sisley's sizing can vary between collections and fabric types, so always cross-reference with the measurements on their product pages.

Sisley Sizing by Garment Type

Blazers and tailored jackets — this is where the small-running issue is most pronounced. Sisley's tailoring is genuinely excellent — sharp, Italian, beautifully constructed — but it is cut for a narrow-shouldered, slim-hipped frame. I'd say size up two sizes for blazers if you want to wear anything underneath, or one size if you plan to style it open over a fine-knit or T-shirt.

Trousers and jeans — similarly, go up at least one size. Sisley's denim in particular is notorious for coming up small through the thigh and hip. Their straight-leg and wide-leg cuts offer a little more flexibility than the skinny styles, but a size up is still the safe call.

Dresses — it depends on the style. Their wrap dresses and bias-cut styles are more forgiving and true to EU sizing. Bodycon or fitted shift styles? Size up without question.

Knitwear — Sisley's knitwear is where I genuinely think they outshine a lot of the competition. The quality is superb. Slim-fit styles come up small, so I'd size up one. Their oversized knits, on the other hand, are quite generously cut — stick to your usual EU equivalent here.

Coats — go up one size as a minimum, two if you plan to layer underneath. Their outerwear is stunning but the shoulder seam placement is unforgiving if you size wrong. When in doubt, size up and belt at the waist to pull it in — it will look intentional and absolutely brilliant.

A Few Practical Tips Before You Order

Always measure your bust, waist and hips before ordering, and compare directly to Sisley's size guide on their website — don't guess from your UK size alone.
Check the fabric composition on each item. A wool-rich coat with no stretch needs more size allowance than a jersey top with 5% elastane.
Sisley's return policy allows returns within 30 days of receipt for unworn items — so ordering two sizes and returning one is a perfectly sensible strategy.
Customer reviews on individual product pages often mention fit — scan these quickly before buying. If multiple reviewers say "size up," listen to them. They're right.

Best High Street & Premium Alternatives to Sisley

Sisley occupies an interesting spot in the market — contemporary, trend-led, Italian-influenced, with a confident edge and genuinely impressive quality for the price. If you love the aesthetic but want more sizing flexibility (or a lower price point), here are the brands I'd point you towards:

High street alternatives:

Mango — The closest match to Sisley's European aesthetic at a more accessible price. Spanish, trend-savvy, and their tailoring in particular has been getting excellent press coverage lately. Sizing is also more accommodating for UK bodies than Sisley.
Massimo Dutti — Also part of the Inditex family but positioned more premium. Impeccable quality for the price, and the restrained Italian-inspired aesthetic is very Sisley. Their tailoring is genuinely brilliant.
COS — If you love Sisley's cleaner, more architectural pieces, COS is the obvious parallel. Sizing is generally true to UK sizes and the construction quality is exceptional for the price point.
French Connection — A great option for Sisley-adjacent occasion dressing and smart-casual pieces. Their dresses and jumpsuits tend to be well cut and sizing is reliable.
All Saints — For Sisley's edgier, more fashion-forward side. All Saints does that relaxed-but-cool London aesthetic brilliantly, with great leather alternatives and relaxed tailoring.
Reiss — When you want Sisley's sharp tailoring energy without the Italian sizing drama. Reiss is consistently well cut for UK bodies and the quality is excellent across their blazers and trousers.
Warehouse — Underrated for trend-led, well-priced pieces that capture that contemporary European feel. Great for seasonal dresses and workwear basics at an accessible price.
Urban Outfitters — For Sisley's more directional, fashion-forward pieces, Urban Outfitters punches well above its price bracket. Their co-ords and tailored separates in particular are worth a look.

Premium alternatives:

Claudie Pierlot — Parisian contemporary fashion that shares Sisley's polished, trend-confident energy. The quality is superb and sizing tends to be more consistent for UK shoppers.
Hush — For Sisley's quieter, more refined pieces. Hush does incredibly wearable, well-made separates and the sizing is very true-to-UK, which makes it a stress-free buy.

Luxury / designer alternatives:

The Kooples — French, effortlessly cool, with that same contemporary edge that defines Sisley. Pricier, but the rock-and-roll tailoring is genuinely in a league of its own.
IRO Paris — Another French label with a confident, slightly sensual aesthetic that mirrors Sisley's Italian approach to dressing. Their leather jackets are particularly iconic.

Two independent brands worth knowing:

Samsøe Samsøe — A brilliant Danish label that doesn't get nearly enough attention in the UK. Understated, beautifully made, and with a clean Scandinavian take on contemporary dressing that shares Sisley's restrained sophistication. Sizing is generous and consistent.
LF Markey — A London-based independent brand making relaxed, unfussy separates with real character. Their trousers, in particular, are a cult buy — roomy, well-cut and incredibly flattering. A brilliant option if Sisley's slim cut doesn't work for your shape but you love the aesthetic.

Take the Guesswork Out of Sisley Sizing

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