This tool helps expectant and new mothers find their correct nursing bra size. It uses standard bra sizing measurements to provide accurate fit recommendations. Properly fitted nursing bras improve comfort during breastfeeding.
🤱 Nursing Bra Size Calculator
Find your perfect fit in seconds
Your Nursing Bra Size Results
How to Use This Tool
Using the nursing bra size calculator takes just a few seconds and requires two simple body measurements.
- Measure your underbust (band) size: Wrap a soft measuring tape snugly around your ribcage, just under your bust. Exhale fully and note the measurement in inches.
- Measure your fullest bust size: Wrap the measuring tape around the fullest part of your bust (usually across the nipples) without pulling tight. Note the measurement in inches.
- Select your preferred cup style and band fit preference from the dropdown menus.
- Click "Calculate Size" to see your recommended nursing bra size and fit notes.
- Use the "Reset" button to clear all inputs and start over, or "Copy Results" to save your size to your clipboard.
Formula and Logic
This calculator uses standard bra sizing conventions adjusted for nursing bra fit needs.
- Band size is derived directly from your underbust measurement, with optional adjustments for fit preference: loose fit adds 1 inch to the band, tight fit subtracts 1 inch.
- Cup size is determined by the difference between your fullest bust measurement and your underbust (band) measurement:
- 0-1 inch difference: AA or A cup
- 2 inches: B cup
- 3 inches: C cup
- 4 inches: D cup
- 5 inches: DD/E cup
- 6 inches: DDD/F cup
- 7 inches: G cup
- 8 inches: H cup
- 9+ inches: I+ cup
- Fit notes are generated based on cup size and band fit preference to provide personalized recommendations.
Practical Notes
Nursing bra fit is especially important for comfort during breastfeeding, as breast size can fluctuate day-to-day with milk supply.
- Measure yourself bare-chested for the most accurate results, preferably at the end of the day when your bust is slightly fuller.
- If you are between band sizes, size up for a looser fit or down for more support, using the band fit preference dropdown to adjust.
- Nursing bras should fit snugly on the tightest hook when first purchased, as the band will stretch over time with regular washing.
- For sleep bras, a slightly looser band and stretchier cup is recommended to avoid restricting milk flow or causing discomfort.
- Always try on bras before purchasing if possible, as sizing can vary slightly between brands.
Why This Tool Is Useful
Properly fitted nursing bras prevent common issues like shoulder pain, back pain, and mastitis caused by poor support.
- Saves time compared to in-store fittings, which may not be available or convenient for new mothers.
- Accounts for fit preferences and style needs, so you get recommendations tailored to how you plan to use the bra.
- Reduces the risk of purchasing ill-fitting bras that need to be returned, saving money and hassle.
- Provides clear fit notes to help you choose features like wide straps or clip-down cups that match your needs.
Frequently Asked Questions
What if my bust measurement is smaller than my band measurement?
This usually indicates an error in measurement. Recheck your underbust measurement to ensure you are measuring snugly against your ribcage, not over clothing. If the measurement is correct, you may need a bra with a stretchy band or a smaller band size than calculated.
Can I use this calculator if I am pregnant and not yet breastfeeding?
Yes, but keep in mind that your bust size may increase further once your milk comes in. Consider sizing up 1 cup size if you are in late pregnancy to account for postpartum changes.
How often should I remeasure for nursing bras?
Breast size can fluctuate significantly in the first 6 weeks postpartum. Remeasure every 2-4 weeks during this period, and then every 3 months once your supply regulates.
Additional Guidance
When shopping for nursing bras, prioritize features that match your daily routine.
- Look for bras with one-handed clip-down cups if you will be breastfeeding frequently in public or while holding your baby.
- Choose moisture-wicking fabrics if you tend to leak milk, to keep your skin dry and prevent irritation.
- Invest in at least 3 nursing bras: one to wear, one to wash, and one spare for emergencies.
- Avoid underwire bras in the first 6 weeks postpartum, as they can restrict milk ducts and increase the risk of mastitis.