The Fastest, Easiest Way to Interpret a Sizing Chart

The fastest way to interpret a sizing chart is to check one thing before anything else: whether the numbers are body measurements or garment measurements. Get that right and the rest takes thirty seconds — compare the chart against your own bust, waist and hips, and pick the size that fits your largest measurement. Get it wrong and you will order a blazer that fits like cling film, which I have done, in front of a client, the week of a shoot.

Step one: work out what you are actually looking at

Almost every sizing chart falls into one of two camps, and brands rarely make it obvious which one you are reading.

Body measurements — the size of the person the garment is designed to fit. Usually headed "to fit" or "body measurements". Standard across most UK high street.
Garment measurements — the item measured flat, then doubled. Usually headed "chest across", "flat measurement", "half chest", or listed alongside sleeve and back length.

The giveaway is the language. Words like bust, waist and hip point to your body. Words like across chest, hem width, back length and sleeve point to the garment. If a chart gives you length figures, it is almost always a garment chart.

My own fail: I once ordered a wool blazer listed at 92cm chest, assumed it was a body measurement, and it turned up as a flat garment figure with zero ease built in. I could not lift my arms. Thirty seconds of reading the column header would have saved me the return.

Step two: the sixty-second method

Measure once, properly. Bust at the fullest point, waist at the narrowest, hips at the fullest — usually about 20cm below the waist. Tape parallel to the floor, snug but not pulled tight.
Save the numbers in your phone. This is the single biggest time-saver in shopping. You will use them hundreds of times.
Find your three numbers on the chart and size to the largest. If your bust says 12 and your hips say 14, take the 14 for anything fitted through the hip and the 12 for anything cropped above it.

That's the whole method. Everything else is refinement.

Step three: add ease if it's a garment chart

Ease is the breathing room between your body and the fabric. If you are reading garment measurements, you have to add it yourself:

Structured wovens (shirts, blazers, tailored trousers) — add roughly 5–10cm to your body measurement.
Jersey and knits with elastane — you can go equal or even slightly under. Stretch does the work.
Coats worn over layers — add 10–15cm. A coat that fits over a T-shirt is useless in January.

The details most people scroll straight past

Model height and size worn. Usually one line under the description. If she is 5'10" in a size 8 and you are 5'3", the length on that midi will land somewhere unfortunate.
Fabric composition. 2–5% elastane buys you forgiveness. 100% cotton or linen does not.
Length measurements. The most ignored figure on any chart and the one that ruins the most dresses.
Reviews mentioning fit. Three people saying "runs small" is more reliable than any chart.

My win, for balance: I bought a jumpsuit for a wedding purely on the inside leg figure — 78cm, which I knew would work with a low block heel. Never tried it on. Wore it twice that summer.

Brands whose sizing charts are genuinely worth trusting

High street

Uniqlo — publishes actual garment measurements product by product. The gold standard for transparency.
M&S — consistent across categories, with petite, curve and long options clearly charted.
Boden — detailed body and garment figures side by side, plus honest fit notes.
Seasalt Cornwall — clear, relaxed fit descriptions so you know what you are getting before it arrives.
Whistles — lists model height and size worn on nearly every product.
Hobbs — tailoring-led, so the chart genuinely reflects the cut.
Jigsaw — reliable between seasons, which matters more than people realise.
Next — straightforward charts with tall and petite variants properly separated out.

Premium

Reiss — precise tailoring measurements; size to your shoulder and bust, not your waist.
Me&Em — excellent length options and clear fit guidance on every piece.
Baukjen — sizing built around real body measurements, with useful styling notes.
Sézane — French sizing, so always check their conversion notes before ordering.

Luxury and designer

Max Mara — Italian sizing runs neat through the shoulder; size up for coats.
Totême — deliberately oversized silhouettes, so read the garment measurements, not the label size.
Joseph — narrow, precise cut. Their chart is accurate but unforgiving.

Two independents worth knowing

Isabella Wren — a small British label that sizes almost entirely by body measurement rather than label size.
Kemi Telford — London-based, joyful prints, and unusually clear about how each style actually sits.

Or skip the chart entirely

This is exactly why I built Tellar. It is the UK's leading sizing tool — your body matched precisely to over 1,500 brands, instantly. You measure once, using bust, waist and hip, or simply enter a brand size you already own and trust. Then use the Store Size Lookup to get your exact size in any brand: COS, Reiss, Everlane, Arket and hundreds more. It is always free, needs no downloads, and works straight in your browser.

There is also the Tellar Fashion Hub — a library stacked with free posts from our top stylists. Honest, unbiased, independent and always free. Style advice, top picks and the best brands, with no one paying to be there.

Never read a size guide again

Measure once. Get your exact size in 1,500+ brands. Free, instant, no downloads.

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