What is Sizing Like at Sacai?

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

Sacai runs small — typically one to two sizes smaller than your usual UK size — and uses Japanese numeric sizing (1, 2, 3, 4) rather than any conventional UK or EU labels, which genuinely catches people off guard when they're buying from the brand for the first time. I speak from painful personal experience here. I ordered a Sacai shirt-dress online years ago, convinced that a size 3 was going to be my perfect fit based on some very confident mental arithmetic. It arrived, I tried it on, and I genuinely could not get my arms through it properly. Returned, reordered in a 4, and it was everything I'd dreamed of. So. Please learn from my mistakes before you spend £500-plus on something that won't do up.

Here's everything you actually need to know before you click buy.

Understanding Sacai's Sizing System

Sacai is a Tokyo-based label founded by designer Chitose Abe, who cut her teeth at Comme des Garçons before launching her own brand in 1999. Like most Japanese luxury labels, Sacai sizes using Japanese conventions — that means numeric labels from 1 to 4, with no Small, Medium, Large to anchor you. The range rarely extends beyond a size 4 either, which remains a genuine shortcoming for a brand of this calibre and price point.

What makes Sacai's sizing particularly tricky is the construction itself. The brand is famous for hybrid, deconstructed pieces — a shirt that is simultaneously a shirt and a knitwear layer, a coat with an unexpected pleated back panel, trousers that are two fabrics sewn into one. These structural choices mean that even within the correct size, fit varies considerably from piece to piece. Measurements really do matter here more than the label number alone.

The golden rule: size up by one, possibly two, from your normal UK size.

Sacai Size Conversion Table

Sacai SizeUK SizeEU SizeUS SizeBust (cm)Waist (cm)Hips (cm)16–834–362–480–8460–6486–9028–1036–384–684–8864–6890–94310–1238–406–888–9268–7294–98412–1440–428–1092–9672–7698–102

Always cross-reference these against the specific garment measurements on the product page before purchasing — Sacai's own size guide on their website is quite reliable, and retailers like Net-a-Porter and Selfridges tend to include detailed measurements per piece.

Sacai Tops, Shirts & Knitwear

This is the category where Sacai's genius is most obvious — and where the sizing quirks are most pronounced. Sacai shirts often feature layered back panels, double collars, or asymmetric hems, meaning the cut through the body and shoulders is complex. I'd always recommend checking the shoulder measurement specifically, as Sacai's structured shoulders can be unforgiving if you're buying too small.

If you're a UK 10, a Sacai size 2 is your starting point — but size 3 if you're broader in the shoulders or have a fuller bust.
Knitwear tends to have slightly more give and can run a little more generously — but don't be lulled into going down a size.
The hybrid knit-shirt pieces (their signatures) are best sized for your largest measurement.

Sacai Trousers & Skirts

The trousers are genuinely some of the most wearable pieces in the range, partly because Sacai loves a wide-leg, pleated cut which is naturally more forgiving. A size 2 comfortably covers a UK 10-12 through the waist and hip, but if you carry more volume in the hip, go to a 3. The skirts — often hybrid with sheer underlayers, or asymmetric in length — follow a similar logic. The waistbands can be fairly structured, so measure carefully before ordering.

Sacai Outerwear & Jackets

Here's a category where you can breathe a little. Sacai's coats and jackets are designed with layering in mind — the whole brand ethos is built around wearing interesting things under interesting things — so the cut is naturally a little more generous through the body. A size 2 works well for a UK 10-12 if you plan to wear fine knits underneath; go to a 3 if you want to layer heavily or if you're buying a more structured blazer-style jacket.

Sacai Dresses

Sacai dresses are spectacular and maddening in equal measure, often because they're doing two structural things at once — sheer over solid, shirt over knitwear, short over long. My honest advice: ignore the size label and go straight to the measurements. Check bust first, then waist. If the bust fits, the rest usually works because of the way the pieces are constructed. If in doubt between sizes, always go up.

Where to Shop If Sacai Is Out of Budget

Sacai sits firmly in the luxury bracket, with most pieces landing between £300 and £1,200. If you love the aesthetic — that layered, deconstructed, intellectually rigorous approach to dressing — here are some alternatives at different price points that really deliver:

High Street Options:

COS — The spiritual high-street sibling of Sacai. Clean lines, architectural cuts, considered fabrics. Genuinely the best high-street approximation of that Japanese-influenced minimalism.
Whistles — Elevated, unfussy, and very wearable. Their layered pieces and modern tailoring hit a similar note without the price tag.
All Saints — For the edgier, darker side of Sacai's aesthetic. Their leather pieces and asymmetric cuts are genuinely good quality for the price.
Massimo Dutti — Brilliant for the tailoring side of things. Quality fabrics, clean cuts, and a quiet confidence that echoes Sacai's ethos at a fraction of the cost.
Reiss — Reliable and very well-made. Their structured pieces and trousers are particularly strong if you're chasing that polished layered look.
Me&Em — A genuinely excellent British brand that punches well above its price point. Their knitwear and tailoring are superb, and the sizing is consistent and reliable.
Anthropologie — More eclectic, more maximalist than some of the above, but genuinely interesting pieces that reward the kind of creative dressing Sacai encourages.

Premium & Luxury Options:

Rejina Pyo — A Korean-British designer based in London whose work shares Sacai's love of unexpected construction and precise, sculptural silhouettes. Independent, brilliant, and significantly more accessible than Sacai. Highly recommended if you haven't discovered her yet.
Nanushka — The Budapest-based label that does that elevated minimalism with beautiful, considered fabrics (their vegan leather pieces in particular). A natural step between high street and full luxury spend.

Never Guess Your Size Again — Use Tellar

Sacai's Japanese numeric sizing is genuinely one of the trickiest systems to navigate — and getting it wrong on a £600 dress is not the kind of lesson anyone wants to learn twice. That's exactly why Tellar.co.uk exists.

Tellar is the UK's leading clothing sizing tool — free, unsponsored, and completely independent. Here's how it works:

Measure once — using your bust, waist, and hip measurements, or simply your size in a brand you already know fits you well.
Use the Store Size Lookup tool to get your precise size across 1,500+ brands — Sacai, COS, Reiss, Arket, Net-a-Porter brands, and hundreds more — instantly.
Always free — no downloads, no account needed, works entirely in your browser.

Plus, explore the Tellar Fashion Hub — a library of free, honest, unbiased style posts from our team of stylists covering every fashion question you've ever had. No sponsored content, no brand deals, no agenda. Just good advice.

Find My Sacai Size →