Prom Dress Size Calculator

Your prom size, in both systems

Q: Are prom dress sizes the same as regular dress sizes?

Not exactly. Many prom dresses are cut on the juniors block — odd numbers (1, 3, 5, 7…), a straighter waist and less bust shaping than misses sizing. A junior 9 is roughly a misses 8. Some formal brands use misses sizing instead, which is why this calculator shows you both numbers.

Prom dresses come in two sizing systems — juniors (odd numbers) and misses (even) — and brands rarely tell you which they're using. Enter your measurements; get both answers.

Calculate your prom size

Free · No sign-up

Bust in

Around the fullest point

Waist in

Your natural waist

Hips in

Around the fullest point

Juniors size (odd numbers)

—

Most prom labels use this

Misses size (even numbers)

—

Some formal brands use this

Enter your measurements — both sizes appear as you type.

Juniors vs misses

Two blocks, one fitting room

Juniors sizing (1, 3, 5 … 15) is drafted for a younger figure: a higher, straighter waist, less difference between bust and waist, and a shorter bodice. Misses sizing (0, 2, 4 … 20) assumes more shaping through the bust and hip.

Prom sits awkwardly across both. Big formal labels split: some cut juniors, some misses, and a few publish their own charts that match neither. The honest workflow is the one this page uses — measurements first, both candidate sizes shown, then the brand's chart decides.

Juniors	≈ Misses
1 – 3	0 – 2
5	4
7	6
9	8
11	10
13	12
15	12 – 14

The juniors chart

Junior dress sizes 1–15

Junior size	Bust up to	Waist up to	Hips up to
Junior 1	32″ / 81.5 cm	24″ / 61 cm	34″ / 86.5 cm
Junior 3	33″ / 84 cm	25″ / 63.5 cm	35″ / 89 cm
Junior 5	34″ / 86.5 cm	26″ / 66 cm	36″ / 91.5 cm
Junior 7	35″ / 89 cm	27″ / 68.5 cm	37″ / 94 cm
Junior 9	36.5″ / 92.5 cm	28.5″ / 72.5 cm	38.5″ / 98 cm
Junior 11	37.5″ / 95.5 cm	29.5″ / 75 cm	39.5″ / 100.5 cm
Junior 13	39″ / 99 cm	31″ / 78.5 cm	41″ / 104 cm
Junior 15	40.5″ / 103 cm	32.5″ / 82.5 cm	42.5″ / 108 cm

Worked examples

Three prom matches, traced

34 / 26 / 36

→ Junior 5 · Misses 4

A textbook match in both systems — every measurement lands in the same row. If a dress this size doesn't fit, the brand's chart is off-standard, not you.

36 / 28 / 38

→ Junior 9 · Misses 8

The one-step offset between the systems in action: same body, two labels, junior number exactly one odd step above the misses number.

39 / 31.5 / 42

→ Junior 15 · Misses 12

At the top of the juniors chart the systems drift further apart — the waist and hips outgrow the junior block first. If this is you, misses-cut formals will usually fit better than juniors.

Prom-specific fit notes

What the chart can't tell you

Boned bodices forgive nothing

A boned, fitted bodice fits like tailoring: your waist measurement is the whole game. If your waist is your largest relative measurement, order to it and have the bust taken in.

Length is ordered, not sized

Formal dresses ship long on purpose. Your size is set by bust/waist/hips; your height and heels decide the hem, which a tailor sets at the end. Don't size up or down chasing length.

Online prom brands vary wildly

The cheapest online formal labels are the least standard charts in this whole site. Measure, compare against their chart line by line, and read the returns policy before ordering.

Measure like a formal shop does

Four steps before you order

Wear the underpinnings

Measure in the bra you'd wear with the dress — strapless if the dress is strapless. It changes the bust number and where the bodice sits.

Tape flat, not tight

Bust at the fullest point, waist at the natural crease, hips at the fullest point. Snug, level, and over thin clothing — formal fabrics forgive nothing, so the numbers must be true.

Note your height + heels

Not for size — for length. Formal dresses are cut long and hemmed to you; knowing your height in your prom shoes saves a surprise at the tailor.

Match to their chart

Run this calculator for your junior and misses numbers, then compare your actual measurements with the specific brand's chart line by line. Their chart wins any tie.

Questions

Before you ask

Are prom dress sizes the same as regular dress sizes?

Not exactly. Many prom dresses are cut on the juniors block — odd numbers (1, 3, 5, 7…), a straighter waist and less bust shaping than misses sizing. A junior 9 is roughly a misses 8. Some formal brands use misses sizing instead, which is why this calculator shows you both numbers.

How do I know if a prom dress is junior or misses sized?

Odd numbers (1–15) mean juniors; even numbers (0–20) mean misses. If a listing shows S/M/L only, the brand's own chart is the only reliable guide — ask for the bust, waist and hip measurements behind the letter.

Should I measure with the bra and shoes I'll wear?

Yes for both, ideally. The bra changes your bust measurement and posture of the bodice; heels don't change your size but decide the hem length, and formal dresses are almost always ordered long and hemmed. Measure for size in the underpinnings you plan to wear.

What if I'm between sizes in a prom dress?

Size up, especially in fitted and mermaid styles. Formal fabrics have no stretch and formal alterations are priced accordingly — taking in is straightforward, letting out usually isn't possible. In a flowy A-line, the smaller size can work if only your hips are over the line, since the skirt skims them.

When should I order a prom dress?

Earlier than feels reasonable — the popular styles in the popular sizes sell out by mid-season, and you want 3–4 weeks of slack for alterations. If you're ordering online, order the moment you have your measurements, and check the returns policy before you fall in love with a final-sale dress.

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Reference

Full Size Chart

Every size in US, UK, EU and AU — with cm, plus and petite tables included.

See the full chart →

Who made this · How it's sourced

Built by a person, checked against sources

Ian Welkins

Builder & maintainer

I build small, single-purpose calculators and check every number they print. This one exists because dress sizing is a mess of unregulated charts — the least I could do was gather the published ones in one place and show the working.

Found a chart that disagrees with ours? That's exactly what the report-an-error page is for — corrections get checked and the page gets updated.

Last verified: November 2026 · Charts re-checked against the sources listed here

Methods & sources

ASTM D5585Standard tables of body measurements for adult female misses figure type
ISO 8559Size designation of clothes — anthropometric survey definitions
Published brand charts (consensus)Cross-checked across major retailers' published size charts; where brands disagree, the median value is used and the variance disclosed

Method in one line: match each measurement to the consensus chart, round up between sizes, let the largest measurement govern — then adjust for the style of dress.