Size Guide | ActiveForm Women

How to Measure Yourself

For the best fit, take your measurements while wearing a non-padded, well-fitting bra. Use a soft measuring tape and keep it snug but not tight. Measure twice for accuracy!

Measure Your Band Size

Wrap the tape firmly around your ribcage, directly under your bust. Ensure the tape is parallel to the ground and level all the way around. Note this measurement in centimetres.

Measure Your Bust Size

Wrap the tape around the fullest part of your bust (usually across the nipple line). Keep it parallel to the floor and make sure it's not too tight. Note this measurement.

Calculate Your Cup Size

Subtract your band measurement from your bust measurement. Each centimetre of difference corresponds to a cup size: 0–1cm = A, 2–3cm = B, 4–5cm = C, 6–7cm = D, etc.

Measure Your Waist & Hip

For underwear sizing: measure your natural waist at its narrowest point, and your hips at their widest point. Use the tables below to find your size.

Reference Charts

Size Charts

AU Size	Band (cm)	Bust (cm)	Cup	US Equiv.	UK Equiv.
XS	63–68	78–82	A/B	XS (30A–30B)	XS (30A–30B)
S	70–75	82–87	B/C	S (32B–32C)	S (32B–32C)
M	76–82	87–93	C/D	M (34C–34D)	M (34C–34D)
L	83–90	93–99	D/DD	L (36D–36DD)	L (36D–36E)
XL	91–98	99–105	DD/E	XL (38D–38DD)	XL (38E–38F)
XXL	99–108	105–114	E/F	XXL (40DD–40E)	XXL (40F–40FF)

💡 Tip: For high-impact activities, we recommend sizing down for extra compression. If you're between sizes, go up for comfort or down for more support.

AU Size	Waist (cm)	Hip (cm)	US Equiv.	EU Equiv.
XS	60–64	85–89	XS	32–34
S	65–69	90–94	S	36
M	70–75	95–100	M	38–40
L	76–82	101–106	L	42
XL	83–90	107–113	XL	44–46
XXL	91–100	114–122	XXL	48

💡 Tip: Our seamless underwear has excellent stretch. If you're between sizes, we recommend your larger size for the most comfortable fit.

Set Size	Bra Band (cm)	Bust (cm)	Waist (cm)	Hip (cm)
XS	63–68	78–82	60–64	85–89
S	70–75	82–87	65–69	90–94
M	76–82	87–93	70–75	95–100
L	83–90	93–99	76–82	101–106
XL	91–98	99–105	83–90	107–113
XXL	99–108	105–114	91–100	114–122

💡 Tip: When buying a set, size according to whichever measurement falls in the larger size category. The bra and briefs are sold separately so you can mix sizes.

AU/NZ	US/CA	UK	EU	IT	FR	JP
XS	XS (0–2)	6–8	32–34	36–38	36–38	5–7
S	S (4–6)	8–10	36	40	40	9
M	M (8–10)	12–14	38–40	42–44	42–44	11–13
L	L (12–14)	16–18	42	46	46	15–17
XL	XL (16)	20	44–46	48	48	19
XXL	XXL (18–20)	22–24	48	52	52	21

Quick Tool

Quick Size Finder

Answer a few quick questions and we'll recommend your best size.

Step 1 of 3

What is your band measurement?

Step 2 of 3

What activity will you primarily use this for?

Step 3 of 3

Do you prefer a snug or relaxed fit?

We recommend size M

Based on your measurements and preferences, a Medium will give you the perfect blend of support and comfort for your chosen activity.

Shop Your Size →

Expert Advice

Fit Tips from Our Experts

✅

Signs of a Perfect Fit

The band should sit flat and level all the way around. Straps shouldn't dig in or fall off. Cups should lie flat with no gaps or spillage. You should be able to fit two fingers under the band.

Perfect Fit

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Signs You Need to Size Up

If the band rides up at the back, the cups have visible gaping, you're spilling out of the cups, or the underwire sits on breast tissue rather than at the base — try the next size up.

Too Small

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Signs You Need to Size Down

If the band moves up and down during exercise, the straps fall off your shoulders, or the cups wrinkle — the bra is too large. Try a size down for better support.

Too Large

Still unsure? Our team is happy to help you find your perfect fit.

Ask a Fit Expert →