Size guide

Find your bra size
in 2 measurements, in 2 minutes

No expertise needed — a measuring tape is enough. Follow the steps below and our calculator gives you your exact size.

1

Get ready

What you need: a soft measuring tape (the dressmaker kind, not rigid).

Position: stand up straight, without puffing out your chest. Ideally, wear an unpadded bra or no bra at all.
2

Take your 2 measurements

📏
Measurement ①
Underbust
Place the tape right under your breasts, level, snug but not tight. Write down the value in cm.
📐
Measurement ②
Bust
Wrap the tape around the fullest part of your bust (at the nipple line), keeping it level.
📌 Example: underbust = 78 cm · bust = 88 cm → your size = 90 C-cup
3

Calculate your size

Size calculator

Enter your 2 measurements — your size appears instantly.

📊

Reference charts

Cup — measurement difference

CupDifference (cm)
A1 – 4 cm
B4 – 8 cm
C8 – 12 cm
D12 – 15 cm
E15 – 18 cm
F18 – 21 cm
G21 – 24 cm
H24 – 28 cm

Underbust → Size

Measurement (cm)Size
63 – 67 cm80
68 – 72 cm85
73 – 77 cm90
78 – 82 cm95
83 – 87 cm100
88 – 92 cm105
93 – 97 cm110
98 – 102 cm115
103 – 107 cm120
108 – 112 cm125
💡 If you're between two sizes: go up on the band (more comfort) and up a cup if your bust slightly overflows.
✓

How do you know the size is right?

✅ The band sits horizontally without riding up toward your shoulders
✅ The cups enclose the bust well, without folds or spillage
✅ The straps stay in place without digging in or slipping off your shoulders
✅ You can slide 2 fingers under the band without pulling hard
❌ Band rides up → band too loose, go down one size
❌ Bust overflows → cup too small, go up one cup
❌ Straps dig in → they're compensating for a loose band, adjust the band first
❌ Folds in the cups → cup too big, go down one cup

Know your size?

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See the WonderGel+ →