Reviewed
40G (UK 40F) bra size
A 40G has a 40-inch band and a G cup, about 7 inches between band and bust. In the UK it is 40F, in Australia 18F and in Europe 90G.
- US
- 40G
- UK
- 40F
- AU
- 18F
- EU
- 90G
- FR
- 105G
Also fits (sister sizes): 38H firmer band · 42DDD looser band · all same-volume sizes ↓
40G measurements
- Snug underbust
- 40–41 in · 102–104 cm
- Bust, fullest part
- about 47 in · 118–121 cm
- Cup difference
- 7 in (G 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.
40G sister sizes
Same cup volume, different band. If a 40G 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 40G doesn't fit
- Band rides up at the back
- Try 38H
- Band digs in, cups fit
- Try 42DDD
- Spilling over the cups
- Try 40H
- Cups gape or wrinkle
- Try 40DDD
Not sure what's wrong? Run through the 4-point fit check.
40G questions
What is the sister size of 40G?
38H (one band down, one cup up) and 42DDD (one band up, one cup down). Sister sizes hold the same cup volume on a different band.
What is 40G in UK, Australian and European sizes?
UK 40F, Australia 18F, Europe 90G and France 105G. US and UK cup letters match up to DD and then split.
What measurements are a 40G?
A snug underbust of about 40–41 in (102–104 cm) and a bust of about 47 in (118–121 cm). Measure with the tape level and use the calculator for an exact result.
Is 40G a big size?
40G has a very full cup volume for a 40 band. Cup letters only mean something next to the band: a 40G holds the same as 28M or 30L.