Maternity Bra Sizing Guide: How to Measure Your Correct Size
Your bra size changes during pregnancy. Most women go up 1-2 band sizes and 2-3 cup sizes. Getting maternity bra sizing right
saves money and prevents discomfort.
This guide shows you how to measure for maternity bras in 3 simple steps.
How to Measure for Maternity Bra Sizing
You need 2 measurements: band size and bust size.
What you'll need:
- Soft measuring tape
- Large mirror
- No bra or unpadded bra
- 5 minutes of your time
Step 1:
Measure Your Band Size
Stand straight. Wrap tape around your ribcage directly under your breasts.
Keep tape level and snug but not tight. Breathe normally. Measure on exhale. Round to nearest whole number.
Example:
- 81 cm (32 inches) = Band size 32
- 84 cm (33 inches) = Band size 34
Band size conversions:
- 10 = 81 cm (32 inches)
- 12 = 86 cm (34 inches)
- 14 = 91 cm (36 inches)
- 16 = 97 cm (38 inches)
- 18 = 102 cm (40 inches)
Step 2:
Measure Your Bust Size
Stand straight. Wrap tape around the fullest part of your breasts.
Keep tape level. Don't pull tight or compress breasts. Round to nearest whole number.
Example: 94 cm (37 inches) = Bust measurement
Cup size chart:
| Difference | Cup Size |
|---|---|
| 2.5 cm (1 inch) | A |
| 5 cm (2 inches) | B |
| 7.5 cm (3 inches) | C |
| 10 cm (4 inches) | D |
| 12.5 cm (5 inches) | DD/E |
| 15 cm (6 inches) | F |
| 18 cm (7 inches) | G |
| 20 cm (8 inches) | H |
Calculate Your Cup Size
Subtract band size from bust size. The difference = your cup size.
Example calculation:
- Bust: 94 cm (37 inches)
- Band: 81 cm (32 inches)
- Difference: 13 cm (5 inches) = DD cup
- Your size: 32DD (Australian 10DD)
Measurement Tips
Best time: Morning before breasts swell.
Stand straight: Don't slouch. Affects ribcage measurement.
Breathe normally: Measure on exhale, not deep breath.
Measure twice: Confirm accuracy. Take average if different.
Get help: Partner ensures tape is level.
Write it down: Track measurements over time.
-
Maternity Bra Sizing Calculator
Use this formula:
- Measure band (under breasts): _____ cm
- Measure bust (fullest part): _____ cm
- Calculate difference: bust - band = _____ cm
- Find cup size in chart above
- Your size = Band + Cup
Example:
- Band: 86 cm (34 inches)
- Bust: 99 cm (39 inches)
- Difference: 13 cm (5 inches) = DD
- Size: 34DD (12DD)
-
When to Measure for Maternity Bra Sizing
Your size changes throughout pregnancy. Measure at these key points:
- 16 weeks (4 months): First measurement. Most breast changes happen by 16 weeks. Buy 2-3 maternity bras.
- 32 weeks (8 months): Second measurement. Buy nursing bras for postpartum.
- 2 weeks postpartum: Final measurement after milk comes in and stabilises.
- Every 6-8 weeks: Check fit if bra feels uncomfortable.
International Bra Sizing Chart S, M, L, XL
| US/EU | A | B | C | D | E | F | G | H | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AU | EU | US | UK | A | B | C | D | DD | E | F | FF | |
| 10 | 70 | 32 | 32 | S | S | S | S | S | M | M | ||
| 12 | 75 | 34 | 34 | S | S | M | M | M | M | L | ||
| 14 | 80 | 36 | 36 | M | M | M | L | L | L | L | ||
| 16 | 85 | 38 | 38 | M | L | L | L | L | XL | XL | ||
| 18 | 90 | 40 | 40 | L | L | XL | XL | XL | XL | |||
| 20 | 95 | 42 | 42 | XL | XL | XL | XL | XL | ||||
| 22 | 100 | 44 | 44 |
How to use this chart:
- Find your band size (AU, EU, US, or UK)
- Find your cup size in the header row
- Follow down to find your bra size (S, M, L, XL)
Shop Maternity Bras at Mumgerie
Find your correct bras size at Mumgerie. Australian sizes A-J cups, bands 8-24.
Why shop with us:
- Expert fitting advice
- Free shipping over $150
- Express delivery options
- Curated products by mums
Get maternity bra sizing right. Your body deserves proper support.
Shop now:
Frequently Asked Questions
Re-measure every 6-8 weeks. Your ribcage expands and breast tissue grows throughout pregnancy. Your body changes significantly at different stages.
Key measurement points: 16 weeks, 32 weeks, 2 weeks postpartum.
Choose the larger size. Bras stretch with wear. You can tighten the band using hooks. You can't make a too-small bra bigger.
If between band sizes, try the smaller band with larger cup (same volume). Example: Between 34C and 36C? Try 34D.
No. Buy nursing bras that fit at 32-36 weeks. Your breasts are already close to breastfeeding size.
Expect temporary 1 cup size increase when milk comes in (days 2-5). This settles within 2 weeks. Buy sleep bras 1 size larger for overnight engorgement only.
Band: Sits level around body. Doesn't ride up back. You can fit 2 fingers under band. Feels snug on loosest hook.
Cups: Breast fills cup completely. No overflow at top or sides. No gaps or wrinkles. Nipple points forward.
Straps: Stay on shoulders. Don't dig in. You can fit 2 fingers under strap.
If band rides up, you need smaller band size. If breast spills over, you need larger cup size.
No. Regular calculators don't account for pregnancy changes. Your breasts change shape during pregnancy, not just size.
Use the maternity bra sizing method above. Measure band and bust separately. Calculate difference for cup size.
Don't add 4-5 inches to band measurement. That's an outdated method from the 1930s.
32-36 weeks is ideal. Most breast growth is complete. You're close to final breastfeeding size.
Professional fitting helps if:
- First time buying maternity bras
- Larger bust (D+ cups)
- Unsure about size between brands
- Want expert advice on styles
DIY measuring at home works well for tracking changes and online shopping.
No. Brands size differently:
Cake Maternity (Australian) runs true to size. Consistent band sizing.
Hot Milk Lingerie (New Zealand) runs slightly generous. Band may run large by 1 size.
Panache (UK) runs true to UK sizing. Firm band. Best for larger busts.
Always check brand-specific size charts. When between sizes, choose larger size.