What size am I in vintage? A conversion chart for medium and up

Let me guess. You found a dress you loved, flipped the tag, saw a size 16 or 18, and thought, “Oh good, that’s me.” Then it wouldn’t zip past your ribs.

That was me for years. And it isn’t you. Vintage sizes just don’t mean what today’s sizes mean, and nobody tells you that until you’re stuck in a dressing room.

So here’s the short answer, then the chart, then the part that actually matters: how to know for sure.

Why the numbers changed

There was never one size chart that every brand had to follow. The U.S. government published voluntary sizing standards in 1958 (CS 215-58) and again in 1970 (PS 42-70), but brands could ignore them, and many did.

Over time, the number on the label kept getting smaller for the same body. People call this vanity sizing. Here’s the example that shows it best, from a 2011 New York Times report: in Sears’ 1937 catalog, a size 14 dress had a 32-inch bust. By 1967, a 32-inch bust was a size 8. By 2011, it was a size 0.

Same body. Three completely different numbers.

The vintage size conversion chart

These charts start at the sizes most of us over a medium are actually looking for. All measurements are body measurements in inches (the person the clothes were made for, not the garment itself).

The last two columns are my best match to today’s sizes. I lined each row up against the ASTM D5585 misses chart, which a lot of U.S. brands use as their starting point, and ModCloth’s size chart for letter sizes. Use them as a starting point, not a promise.

1950s store-bought sizes

From the 1955 Sears catalog, as reprinted by Chronically Vintage.

Size on the tag	Bust	Waist	Hips	About today	Letter size
14	35½	27	38	6	M
16	37	28½	40	10	L
18	39	30½	42	12	L to XL
20	41	32½	44	14	XL

Chronically Vintage puts a 1950s size 18 at about a modern 8 or 10, even smaller than my match. That’s because many brands today cut more generously than the standard chart. Either way, the takeaway is the same: the 1950s number is way bigger than the size you’d be.

1970s store-bought sizes

From the 1970 government standard, PS 42-70.

Size on the tag	Bust	Waist	Hips	About today	Letter size
16	38	29	40	10	L
18	40	31	42	12 to 14	XL
20	42	33	44	14 to 16	XL
22	44	35	46	16 to 18	1X

Sewing patterns from 1967 on

If you sew, or you’re buying something someone made from a pattern, these numbers matter. The big pattern companies revised their sizes in November 1967, and today’s Simplicity Misses charts still use the same bust and hip numbers (the waists are about an inch bigger now). The “Women’s” sizes are the larger range. Newer patterns label that range 18W to 32W instead.

Pattern size	Bust	Waist	Hips	Letter size
Misses 14	36	27	38	M
Misses 16	38	29	40	L
Misses 18	40	31	42	L to XL
Women’s 40	44	36	46	1X
Women’s 42	46	38	48	2X
Women’s 44	48	40½	50	2X
Women’s 46	50	43	52	3X
Women’s 50	54	48	56	4X

How to know it’ll actually fit

The chart gets you close. A tape measure gets you sure. Here’s what I do every single time:

1. Measure yourself once. Bust at the fullest part, natural waist at the narrowest part, hips at the fullest part. Write them down. The Fit Decoder walks you through it and saves your numbers on your phone.
2. Get the garment’s numbers. Ask the seller to lay it flat and measure straight across the bust, waist and hips, then double each one. A good seller will. If they won’t, that tells you something.
3. Compare, and leave some room. For a fitted dress with no stretch, look for about 3 to 4 inches more than your bust. That’s the “fitted” ease on the Vogue, Butterick and McCall’s ease chart. For a looser style, 5 inches or more.
4. Check the shoulders on jackets. 1980s pieces especially have heavily padded shoulders, and shoulders are the hardest thing to alter.

If the waist is within an inch or two of yours on a non-stretch dress, it’s going to be snug. If it’s smaller than your waist, it’s a pass, no matter how pretty it is. I know. I’ve been there.

Or skip the math

Sometimes you want the look without the measuring tape and the hunt. That’s what vintage-inspired pieces are for: new clothes cut in the old shapes, sized on today’s charts, and usually made well past XL.

If you save your numbers in the Fit Decoder, each one of these shows whether you’re inside its size range before you click.

And if you want all of this on one page you can keep on your phone or print, grab the free Fit Guide. It has the measuring steps, the size history and a fill-in worksheet for your own numbers.

Happy hunting,
Paige