Reviewed
40C bra size
A 40C has a 40-inch band and a C cup, about 3 inches between band and bust. In the UK it is 40C, in Australia 18C and in Europe 90C.
- US
- 40C
- UK
- 40C
- AU
- 18C
- EU
- 90C
- FR
- 105C
Also fits (sister sizes): 38D firmer band · 42B looser band · all same-volume sizes ↓
40C measurements
- Snug underbust
- 40–41 in · 102–104 cm
- Bust, fullest part
- about 43 in · 108–110 cm
- Cup difference
- 3 in (C 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.
40C sister sizes
Same cup volume, different band. If a 40C 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 40C doesn't fit
- Band rides up at the back
- Try 38D
- Band digs in, cups fit
- Try 42B
- Spilling over the cups
- Try 40D
- Cups gape or wrinkle
- Try 40B
Not sure what's wrong? Run through the 4-point fit check.
Compare 40C
Sizes next to 40C
40C questions
What is the sister size of 40C?
38D (one band down, one cup up) and 42B (one band up, one cup down). Sister sizes hold the same cup volume on a different band.
What is 40C in UK, Australian and European sizes?
UK 40C, Australia 18C, Europe 90C and France 105C. US and UK cup letters match up to DD and then split.
What measurements are a 40C?
A snug underbust of about 40–41 in (102–104 cm) and a bust of about 43 in (108–110 cm). Measure with the tape level and use the calculator for an exact result.
Is 40C a big size?
40C has a very full cup volume for a 40 band. Cup letters only mean something next to the band: a 40C holds the same as 28I or 30H.