CM to Bra Size Converter

Input your underbust and bust in centimeters to see your band and cup size across US, UK, EU, FR, IT, JP, and AU systems. Metric-first workflow plus quick measuring tips.

Start converting in CM How to measure in centimeters

Prefer inches? Switch to the inch converter

Why this converter helps

Metric-first input keeps the calculator locked on centimeters—no manual toggles required.
Instantly shows your equivalent size across US, UK, EU, FR, IT, JP, and AU systems.
Advanced mode lets you add multiple bust positions for more precise cup guidance.

See the 36C bust size in inches breakdown for a real-world example

Three quick steps

Measure your snug underbust

Wrap the tape firmly under your bust in centimeters. Keep it level and record the snug number.

Measure the fullest bust

Stand naturally and note the fullest bust circumference in centimeters. For extra accuracy, grab leaning and lying measurements too.

Enter values & convert

Type the numbers into the converter below. Leave the unit set to CM, then review the international size outputs.

Convert centimeters to bra sizes

Need inches instead? Toggle the unit tabs above the inputs.

Bra Size Calculator

Advanced Mode (ABTF-style)

Use snug/tight underbust and standing/leaning/lying bust to get a recommended try-on range and style tips.

Enable

Measurement Unit:

Band Size (cm)

Bust Size (cm)

Measurement Guide

Band Size

Measure around your ribcage, just below your breasts. The tape should be snug but not tight.

Bust Size

Measure around the fullest part of your breasts, keeping the tape measure parallel to the floor.

Explore sister sizes once you have your base size.

Band conversion cheat sheet

Use the table below to cross-reference centimeter underbust measurements with international band labels.

Global Size Conversion

US/UK	UK	EU	FR	IT	JP	AU/NZ	DE
28AA	28AA	70AA	85AA	3AA	70AA	6AA	70AA
28A	28A	70A	85A	3A	70A	6A	70A
28B	28B	70B	85B	3B	70B	6B	70B
28C	28C	70C	85C	3C	70C	6C	70C
28D	28D	70D	85D	3D	70D	6D	70D
28DD	28DD	70E	85E	3E	70E	6DD	70E
28DDD	28E	70F	85F	3F	70F	6E	70F
28G	28F	70G	85G	3G	70G	6F	70G
28H	28FF	70H	85H	3H	70H	6FF	70H
28I	28G	70I	85I	3I	70I	6G	70I

Lock in accurate measurements

Follow our step-by-step measuring guide for photos and pro tips, then compare how each size presents in the perception guide.

Read the measurement guide View size perception examples

CM to bra size FAQ

Do I need to convert to inches before using this tool?

No. The calculator defaults to centimeters and converts behind the scenes. Simply leave the unit toggle on CM and enter your numbers.

What if my band measurement lands between two sizes?

Check the sister size suggestions after you convert. Dropping one band size and increasing the cup (or vice versa) fine-tunes tightness while keeping cup volume similar.

Will the results work for EU or Asian bra sizes?

Yes. The output includes US, UK, EU, FR, IT, JP, and AU systems so you can match regional labels without extra math.