Understanding 40G Bra Size
A 40G bra size is considered a medium band size with a very large cup size. This size is perfect for people with an average frame and very large breast volume. Let's explore what makes this size unique and how to find the perfect fit.
Is 40G considered big or small?
Fast facts about 40G
- Snug 40 band with a 8-inch cup jump.
- Standing bust around 47.5–48.5 in keeps the cup filled.
- Share cup volume with 42F for band tweaks.
- Always scoop-and-swoop and check the gore for a flat anchor.
How 40G is measured
Band fit
Aim for a snug 38.5–39.5 in underbust so the 40 band stays level without digging.
Cup depth
Standing bust in the 47.5–48.5 in range keeps roughly a 8-inch cup difference.
Support focus
Choose firm wings, fully adjustable straps, and swap sister sizes if the band shifts during wear.
40G bust size in inches
| Measurement | Typical inches | How to capture it |
|---|---|---|
| Snug band (ribcage) | 38.5–39.5 in | Measure firmly under the bust on an exhale, then round to the band label. |
| Standing bust | 47.5–48.5 in | Keep the tape level across the fullest point while standing tall. |
| Band-to-bust difference | ≈8 in | Subtract your snug band from the standing bust to confirm cup depth. |
| Approx. cup depth | 9.5–10.5 in | Measure from the underwire root to the apex on a well-fitting bra. |
40G bust size in centimeters
| Measurement | Typical cm | How to capture it |
|---|---|---|
| Snug band (ribcage) | 97.8–100.3 cm | Measure firmly beneath the bust, then map it to EU/FR/JP band labels. |
| Standing bust | 120.7–123.2 cm | Keep the tape level across the fullest point without compressing tissue. |
| Band-to-bust difference | ≈20.3 cm | Use the difference to double-check your metric cup depth. |
| Approx. cup depth | 24.1–26.7 cm | Trace from underbust to apex on a supportive bra to check projection. |
- Falls inside the 32-36 band range most people wear, giving a familiar fit baseline.
- Requires strategic support and can appear dramatic without the right bra construction.
- Monitor posture and band tension—small shifts change how the size looks.
- Try sister sizes 42F to fine-tune band tension.
Quick reference for 40G
- 40G ≈ band 40 label with a 8-inch cup step.
- Projected bust lands around 47.5–48.5 in.
- Use the calculator to convert this size across US/UK/EU/JP systems.
Ranges are approximations—double-check your own measurements for precision.
40G across popular sizing systems
Match US 40G to the most searched regional labels without leaving this guide.
Currently showing the United States (US) label — copy 40G to match tags instantly.
United States (US)
40G
United Kingdom (UK)
40F
Europe (EU)
90H
France (FR)
105H
Japan (JP)
95H
Australia (AU)
18G
Quick converter
Switch systems and copy the exact label for checkout forms or bra tags.
Need step-by-step help? Jump into the dedicated guides below for measurement nuances and shopping tips.
Perfect For
- Average frames
- Medium ribcages
- Very large breast volume
- Maximum support needs
Recommended Styles
T-Shirt Bras
Perfect for everyday wear under fitted clothing
- Seamless
- Molded cups
- Comfortable
Balconette Bras
Great for creating a natural lift and shape
- Wide-set straps
- Lower cut cups
- Enhancing
Plunge Bras
Ideal for low-cut tops and dresses
- Deep V-neck
- Minimal coverage
- Versatile
How 40G tends to look
40G pairs a 40-band with a 8-inch cup jump, so the silhouette changes with your frame and bra style.
- Keep 42F in mind—they share cup volume while tweaking the band.
- Shape, strap placement, and fabric choice all influence whether the size looks subtle or bold.
40G compared with nearby sizes
Quick reference when you’re deciding whether to change the band, the cup, or both.
- 40F is one cup shallower—switch when 40G wrinkles along the neckline.
- 42F keep the same cup volume but tweak band tightness for comfort.
Sister size playbook
- Try 42F when you need tighter or looser band support.
Fit checks before you buy
When trying on 40G bras, look for these key fit indicators:
- The band should fit snugly around your ribcage
- Cups should fully contain your breasts without spillage
- Straps should stay in place without digging in
- The center gore should lie flat against your chest
- Keep the band parallel to the floor on the middle hook.
- Scoop and swoop tissue into the cups before checking the gore.
- Adjust straps for lift, then reassess comfort after an hour of wear.
Remember that fit can vary between brands and styles. Always try on bras before purchasing to ensure the perfect fit.
Common 40G questions
What size is 40G in other systems?
40G converts to 40F in UK sizes, 90H in EU, 105H in FR, 95H in JP, and 18G in AU.
What does 40G mean?
40G pairs a 40 band with a cup that is roughly 8 inches deeper than the band measurement.
Which sister sizes match 40G?
40G shares cup volume with 42F. Use them to tighten or relax the band.
How can I confirm this is my best fit?
Measure snug and standing bust, check for smooth cup edges, and ensure the band stays level after a few minutes of wear.
Check 40G with our tools
Measure with the calculator, compare sister sizes, and review the perception guide for styling tips.