Calculate My Bust Size
Accurately calculate your bust size with our free tool. Get your bust circumference, recommended bra size, cup size, and body proportion analysis using simple at-home measurements.
Enter Your Measurements
Measure snugly around ribcage, directly under your bust
Measure around fullest part of bust, tape parallel to floor
For body proportion analysis
For body shape analysis
Your Bust Size Results
Bust Circumference:
Band Size Formula:
Cup Size Formula:
Each 1" difference = 1 cup size (1"=A, 2"=B, 3"=C, 4"=D...)
Bust-to-Waist Ratio:
Ideal range: 1.3 - 1.5 for hourglass proportions
Bust-to-Hip Ratio:
≈1.0 indicates balanced proportions
How to Measure Your Bust Size
Prepare for Measuring
Wear a well-fitting, unpadded bra or measure without a bra. Stand straight with arms relaxed at your sides. Use a soft, flexible measuring tape.
Measure Your Underbust
Wrap the tape snugly around your ribcage, directly under your bust where a bra band would sit. The tape should be level and parallel to the floor. Note this measurement.
Measure Your Full Bust
Wrap the tape around the fullest part of your bust, usually at nipple level. Keep the tape level all around without pulling too tight or leaving it too loose.
Optional: Measure Waist & Hips
For body proportion analysis, measure your natural waist (smallest part of torso) and hips (fullest part around buttocks).
Enter Your Measurements
Input all measurements into our calculator to get your bust size, bra size recommendation, and body proportion analysis.
Bust Size Reference Chart
| Bust (in) | Bust (cm) | Typical Bra Sizes | Category |
|---|---|---|---|
| 30-32 | 76-81 | 30A-32B | Small |
| 33-35 | 84-89 | 32C-34C | Small-Medium |
| 36-38 | 91-97 | 34D-36D | Medium |
| 39-41 | 99-104 | 36DD-38DD | Medium-Large |
| 42-44 | 107-112 | 38DDD-40DD | Large |
| 45-47 | 114-119 | 40DDD-42DD | Extra Large |
| 48+ | 122+ | 42DDD+ | Plus |
Understanding Your Bust Measurements
📏 Bust Circumference
Your bust size is the full circumference around the widest part of your chest. This measurement is essential for clothing, swimwear, and understanding your body proportions.
👙 Bra Size
Bra size combines band (underbust) and cup (bust-band difference). Understanding this helps you find properly fitting bras for support and comfort.
⚖️ Body Proportions
Comparing bust to waist and hip measurements reveals your body shape (hourglass, pear, apple, rectangle) for better clothing choices.
📊 Size Categories
Bust categories (small, medium, large) are general guidelines. Every body is unique, and proportions matter more than absolute measurements.
Measurement Tips for Accuracy
- Measure at the same time of day - breasts can swell slightly throughout the day
- Take 2-3 measurements and use the average for best accuracy
- Stand naturally - don't puff out your chest or slouch
- The tape should be snug but not tight enough to indent the skin
- Have someone help if possible for more accurate back alignment
- Re-measure every 6-12 months as bust size can change
Frequently Asked Questions
Wrap a measuring tape around the fullest part of your bust (usually at nipple level) while wearing an unpadded bra or no bra. Keep the tape parallel to the floor and snug but not tight. This measurement is your bust size. For bra sizing, also measure your underbust (ribcage under bust).
Bust size is your actual circumference measurement in inches or centimeters (e.g., 36 inches). Bra size combines your band size (underbust rounded to even number) with cup size (bust minus band difference) to create sizes like 34C or 36D.
Average bust measurements vary by country, age, and body type. In the US, average bust is around 34-36 inches (86-91cm). However, "normal" encompasses a very wide range. Body proportions often matter more than absolute measurements.
Yes, bust size can change due to weight fluctuations, hormonal changes (menstrual cycle, birth control), pregnancy and breastfeeding, menopause, aging, and muscle development from exercise. Regular measuring ensures accurate sizing.
A properly fitting bra: has a band that sits level without riding up (you can fit 2 fingers under), cups that fully contain breast tissue without gaps or spillage, a center gore (front piece) that lies flat against your sternum, and straps that stay in place without digging in or falling off.
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Created by OmniCalculator.space | Last Updated: January 2026