By chest measurement (about 99 cm / 39 in), a men's medium shirt lines up with a women's large. For a looser, true men's-cut drape, size up to a women's XL — see why below.
| Men's | Women's (by measurement) | Approx. chest / bust |
|---|---|---|
| XS | S | 86 cm / 34 in |
| S | M | 91 cm / 36 in |
| M | L | 99 cm / 39 in |
| L | XL | 107 cm / 42 in |
| XL | XXL | 114 cm / 45 in |
Matched by chest/bust circumference. These are approximate and vary by brand.
You'll see both answers online, and neither is simply "wrong" — they're measuring different things. By raw chest circumference, a men's medium and a women's large are about the same (both near 39–40 in), which is what the chart above reflects. But women's tops are cut differently: narrower through the shoulders, more tapered at the waist, and shorter in length. So if your goal is the same relaxed, boxy fit a men's medium gives, many people go up one more letter to a women's XL. Use the measurement chart for a true size match, and size up one letter if you specifically want the loose men's-style drape.
A men's small is about a women's medium by measurement (women's large for a loose fit). A men's large is about a women's XL by measurement. Going the other way, a women's large is roughly a men's medium.
About a women's large by chest measurement; a women's XL if you want the loose men's-cut fit.
Roughly a women's medium by measurement, or a women's large for a relaxed fit.
For the same letter size, yes — women's tops are cut narrower and shorter, which is why converting up a letter or two is common.