How to Measure Yourself for a Bra
Finding your perfect bra starts with accurate measurements. This guide walks you through how to measure your underbust (for band size) and bust (for cup size) at home using simple tools and easy steps.
You can follow these steps on your own, or let our chatbot bra-fitting bestie, Raddi, guide you through the process and do all the math for you!
What You’ll Need
- Soft measuring tape
- Mirror (to check tape placement)
- No bra or top for best accuracy
Step 1: Measure Your Underbust to Get Your Band Size
Take three measurements with the measuring tape around your ribcage, directly under your breasts:
- One wrapping the tape comfortably snug
- One slightly tighter
- One as tight as you can go while still breathing comfortably
Average these three measurements and round to the nearest even number (e.g., 31.25 inches rounds to 32). This is your estimated band size.
Additional Tips:
- Double check that your measuring tape is laying flat against your back, untwisted, and parallel to the floor
- Wrap the tape around your back first and bring the ends together in front to read the number
- If you have a decimal and aren’t sure whether to round up or down:
- For bands 32 and under, round up
- For bands 36 and above, round down
- A well-fitting band should feel snug on the loosest hook, especially if your bra is fairly new
Step 2: Measure Your Bust
Take three bust measurements around the fullest part of your breasts (often at nipple height):
- While standing upright
- While leaning forward 90 degrees
- While lying flat on your back
Average these three measurements.
Additional Tips:
- Make sure your measuring tape is laying flat against your back, untwisted, and parallel to the floor
- Wrap the tape around your back first and bring the ends together in front to read the number
- To get the most accurate measurements, avoid pressing down on your breasts — keep the tape comfortably snug and level
Step 3: Calculate Your Cup Size
Subtract your average underbust measurement (Step 1) from your average bust measurement (Step 2) to get your cup size. Each inch of difference corresponds with a cup letter:
| Difference (inches) | Cup Size |
|---|---|
| 1 | A |
| 2 | B |
| 3 | C |
| 4 | D |
| 5 | DD/E |
| 6 | F |
| 7 | G |
| 8 | H |
| 9 | HH |
| 10 | J |
| 11 | I |
| 12 | K |
Step 4: Get Your Bra Size!
Pair your band size from Step 1 with your cup size from Step 3 to get your bra size!
- For example: a 32 band + 6 inches difference = 32F.
Ready to Find Your Perfect Fit?
Get fitted with Radical’s expert help — because everyone deserves a bra that fits just right.