Reviewed
40D bra size
A 40D has a 40-inch band and a D cup, about 4 inches between band and bust. In the UK it is 40D, in Australia 18D and in Europe 90D.
- US
- 40D
- UK
- 40D
- AU
- 18D
- EU
- 90D
- FR
- 105D
Also fits (sister sizes): 38DD firmer band · 42C looser band · all same-volume sizes ↓
40D measurements
- Snug underbust
- 40–41 in · 102–104 cm
- Bust, fullest part
- about 44 in · 110–113 cm
- Cup difference
- 4 in (D cup)
These are starting points from the band-and-cup method. Brands differ by about a size, so a two-minute measurement beats any chart.
40D sister sizes
Same cup volume, different band. If a 40D band feels too loose, go down a band and up a cup; if it feels tight, go up a band and down a cup.
If a 40D doesn't fit
- Band rides up at the back
- Try 38DD
- Band digs in, cups fit
- Try 42C
- Spilling over the cups
- Try 40DD
- Cups gape or wrinkle
- Try 40C
Not sure what's wrong? Run through the 4-point fit check.
Compare 40D
Sizes next to 40D
40D questions
What is the sister size of 40D?
38DD (one band down, one cup up) and 42C (one band up, one cup down). Sister sizes hold the same cup volume on a different band.
What is 40D in UK, Australian and European sizes?
UK 40D, Australia 18D, Europe 90D and France 105D. US and UK cup letters match up to DD and then split.
What measurements are a 40D?
A snug underbust of about 40–41 in (102–104 cm) and a bust of about 44 in (110–113 cm). Measure with the tape level and use the calculator for an exact result.
Is 40D a big size?
40D has a very full cup volume for a 40 band. Cup letters only mean something next to the band: a 40D holds the same as 28J or 30I.