How Do I Find My Size in Dresses?

By Ella Blake, Tellar Stylist  |  Tellar Fashion Hub

Finding your size in dresses comes down to three key measurements: your bust, waist, and hips — and knowing which one to prioritise for the cut you're buying. That's the honest answer. But the maddening reality is that a size 12 dress at one brand can fit completely differently from a size 12 at another, which is why so many of us end up with wardrobes full of ill-fitting purchases and a complicated relationship with the number on the label.

I've been there. I once ordered what I thought was a failsafe wrap dress from a brand I loved — measured myself, checked the size guide, ordered confidently — and still sent it back because the bust was gaping and the waist sat somewhere around my ribs. Dresses are genuinely the trickiest garment to size for, because unlike jeans (where it's mostly waist and inseam) or a blazer (shoulders and chest), a dress has to work across your entire body at once. Here's how to get it right.

The Three Measurements That Actually Matter

Before you look at any size guide, get yourself a soft tape measure and note down these three numbers:

• Bust: Measure around the fullest part of your chest, keeping the tape parallel to the floor. Don't hold your breath — you want your natural circumference.

• Waist: Find your natural waist (it's usually the narrowest point, roughly an inch above your navel). Measure here, not where your waistband sits.

• Hips: Measure around the fullest part of your hips and bottom, typically about 8–10 inches below your natural waist.

Once you have all three, you'll often find that one of them runs slightly larger relative to the others — this is completely normal and is actually the key to smarter dress shopping. More on that in a moment.

Which Measurement Should You Size For?

This is the question nobody tells you the answer to, and it's the thing that makes the biggest difference. The short version: size for your largest measurement and alter from there if needed — because letting out a seam is always easier than adding fabric that isn't there.

• Fitted or structured dresses (shirt dresses, bodycon, tailored shifts): size for your hips first, then waist. If the dress has boning or structured bodice, check the bust too.

• Wrap dresses and belted styles: size for your bust and hips — the waist can usually be adjusted with the tie or belt.

• Floaty, relaxed or smock styles: these are far more forgiving, but still size for your largest measurement. Going too small in a smock dress defeats the entire aesthetic.

• Empire-line dresses: size primarily for your bust — the skirt falls from under the chest so hip measurements matter less.

Why Every Brand Fits Differently (And What to Do About It)

Here's something the fashion industry doesn't particularly want you to know: sizing is not standardised. At all. Reiss cuts slim and tailored — their dresses tend to run a size small, particularly in the waist and bust. Phase Eight, on the other hand, is well known for generous, wearable sizing that flatters curves beautifully without being restrictive. Coast tends to be true to size but cuts for a longer torso, which is worth knowing if you're petite.

Whistles is consistently excellent for a clean, elegant fit through the body — I find their shift dresses run very true to UK sizing and are a reliable starting point if you're unsure. LK Bennett is another one where the sizing is precise and thoughtful, though again it helps to know your measurements rather than guessing by label. Hobbs has a loyal following precisely because their quality control is exceptional and the cut is consistently reliable — great for occasion dressing when you can't afford to gamble.

At the more everyday end, Mango has dramatically improved its sizing consistency in recent years and is excellent for midi and wrap styles — though their sizing can lean slightly European (i.e. small), so check the cm measurements rather than the UK size label. ASOS is genuinely one of the better places to size-test dresses because they list actual garment measurements (not just body measurements) for most styles, which is how it should be done everywhere.

Two Independent Brands Worth Knowing

For something a bit different — and frankly, better made than most high street options — I'd point you towards Ghost, a brilliant British brand known for their signature floaty satin-finish dresses. Their sizing is generous and beautifully consistent, and the fabric drapes in a way that forgives a lot. Then there's Kitri, a London-based label that's built a cult following for their size-inclusive, carefully considered fit — they list detailed measurements for every style and often note specifically whether a dress fits large or small. For a special occasion dress, Kitri is worth every penny.

Quick Tips That Make a Real Difference

• Always check the actual garment measurements where listed, not just the size guide. A size 14 dress with a 38" bust measurement is a completely different fit to one with a 40" bust.

• If you're between sizes, go up — a dress that's slightly loose can be tailored. A dress that's tight across the back or gaping at the zip cannot.

• For stretch fabrics, you can afford to size down slightly — but for woven, structured or formal fabrics, always size true or up.

• Body shape matters, too. If you're fuller on the hip than the bust, look for A-line and wrap cuts — they're the most universally flattering shapes because they don't require your measurements to be proportional.

• If a dress fits your bust and hips but not your waist — or vice versa — a small alteration from a tailor is almost always worth it for a piece you love.

Stop Guessing — Use Tellar Instead

🧵 Tellar: The UK's Leading Free Sizing Tool

If dress sizing feels like a guessing game, that's because it usually is — unless you use Tellar. Tellar is the UK's leading free clothing sizing tool, matching your exact body measurements to over 1,500 brands instantly. No more size guides, no more returns, no more disappointment when the parcel arrives.

• Measure once — bust, waist, or hips — and Tellar does the rest.

• Use the Store Size Lookup tool to find your precise size at any brand — from Reiss and LK Bennett to ASOS and Whistles.

• Works entirely in-browser. Always free. No downloads, no sign-up faff.

Tellar also has a growing Fashion Hub — a library of free, honest, unbiased style guides written by real stylists (no sponsored content, no brand deals). Whether you're after the Ultimate Clothing Sizing Guide, the Ultimate Guide to Dresses, the latest Jeans Trends for 2025 & 2026, or the Ultimate Guide to Jackets — it's all there, free, whenever you need it.

Dress shopping doesn't have to be a gamble. Know your measurements, understand which one to prioritise for each cut, and use the right tools. Once you stop trusting the number on the label and start trusting your actual body measurements, it genuinely changes everything.