How to Measure Yourself for a Bra at Home: A Step-by-Step Guide

Quick answer

To measure your bra size at home, wear a non-padded bra, wrap a soft tape measure around your ribcage directly under your bust for the band size, then around the fullest part of your bust for the cup size. Subtract the band measurement from the bust measurement to find your cup size. Repeat both measurements once to confirm accuracy.

A bra that fits properly should feel comfortable from morning to night, but many of us are wearing the wrong size without realizing it. Learning how to measure bra size at home takes about five minutes and gives you a reliable starting point before you buy.

This bra size measurement guide walks you through each step, from preparing your tape measure to double-checking your numbers. You do not need a professional fitter or a special appointment. With a soft tape and a mirror, you can get accurate bra measurements yourself.

What you need before you start

Gather a soft tape measure, a mirror, and a non-padded bra. A padded or push-up bra will add volume and throw off your bust measurement, so choose something thin and unpadded. If you do not own a non-padded bra, a fitted tank top or no top at all works just as well.

Stand in front of a mirror so you can keep the tape level and see what you are doing. Wear whatever you normally wear under your clothes, and avoid measuring over thick clothing. The goal is to measure your body, not your outfit.

• Use a soft, flexible tape measure, not a metal ruler or a piece of string that stretches.
• If you are between sizes, note both numbers and try the larger band with a smaller cup, or vice versa.
• Measure at the end of the day when your body is at its natural size, not first thing in the morning.

Step 1: Measure your band size

Wrap the tape measure around your ribcage, directly under your bust. The tape should sit snug against your skin, level all the way around, and parallel to the floor. Breathe normally and exhale fully before you read the number. If the measurement is an even number, that is your band size. If it is an odd number, round up to the next even number.

Keep the tape horizontal. A tape that dips at the back will give you a band size that is too small, which is one of the most common mistakes in a DIY bra fitting. Check in the mirror that the tape is straight across your back.

• Do not pull the tape so tight that it digs into your skin. It should feel snug, not restrictive.
• Write down the number immediately so you do not forget it.

Step 2: Measure your bust size

Wrap the tape around the fullest part of your bust, usually across the nipple line. Keep the tape level and relaxed, without compressing your breast tissue. Stand straight with your arms at your sides. Read the number where the tape meets itself.

This measurement is your bust size. If you are wearing a non-padded bra, make sure the tape sits smoothly over the fabric. If you are not wearing a bra, lift your breasts gently into the position you want them to sit in the bra before measuring.

• Do not pull the tape tight across your bust. A compressed measurement will give you a cup size that is too small.
• If your breasts are different sizes, measure across the fuller side for the most comfortable fit.

Step 3: Calculate your cup size

Subtract your band measurement from your bust measurement. The difference in inches tells you your cup size. A one-inch difference is roughly an A cup, two inches is a B cup, three inches is a C cup, four inches is a D cup, and so on. This is the standard method used in most bra size calculators.

For example, if your band measures 34 inches and your bust measures 37 inches, the difference is three inches, which points to a 34C. Remember that cup size is not absolute. A 34C and a 36B have similar cup volumes but different band sizes.

• If your calculation lands between two cup sizes, start with the larger cup and adjust based on how the bra feels.
• Cup size letters vary slightly between brands, so always check the brand's own size chart when available.

Step 4: Double-check your measurements

Measure both your band and bust a second time to confirm your numbers. Small differences are normal, but if the second measurement is more than half an inch off, measure again. Consistency matters more than perfection when you are learning how to measure yourself for a bra.

Once you have two matching sets of numbers, you have a reliable baseline. Use this as your starting size when you shop, and be prepared to adjust by one band size or one cup size depending on the brand and style.

• Measure in front of a mirror both times so you can keep the tape level.
• If you are unsure, ask a friend to help with the back measurement.

Step 5: Use your measurements to choose a bra

Your measurements give you a starting size, not a final verdict. Different bra styles fit differently. An underwire bra may feel firmer than a lounge bra, and a bralette often has less structure and more stretch. Try your calculated size first, then adjust based on how the band and cups feel.

When you try on a bra, fasten it on the loosest hook. The band should stay level and snug without riding up. The center gore should sit flat against your chest, and the cups should contain your breast tissue without gaps or spillage. If the band rides up, go down a band size. If the cups gap, go down a cup size.

• Always start on the loosest hook so you can tighten the band as the elastic relaxes over time.
• If a bra feels comfortable but the cups wrinkle, try a smaller cup size before giving up on the style.

Your at-home bra measurement checklist

1. Prepare your tools: Find a soft tape measure, a mirror, and a non-padded bra. Stand in good lighting so you can see the tape clearly. Checkpoint: the tape should be flexible and not stretched out.
2. Measure your band: Wrap the tape snugly under your bust, keep it level, exhale, and read the number. Round up to the nearest even number. Common mistake: letting the tape dip at the back, which gives a band size that is too small.
3. Measure your bust: Wrap the tape around the fullest part of your bust without compressing the tissue. Keep the tape level and relaxed. Common mistake: pulling the tape too tight, which gives a cup size that is too small.
4. Calculate your cup size: Subtract your band measurement from your bust measurement. Each inch of difference equals one cup size. Checkpoint: if you are between cup sizes, start with the larger cup and adjust down if needed.
5. Double-check both numbers: Repeat the band and bust measurements once more. If the second set differs by more than half an inch, measure again. Checkpoint: two matching sets of numbers give you a reliable starting size.
6. Try your size in a real bra: Fasten the bra on the loosest hook and check the band, gore, and cups in a mirror. Adjust by one band or cup size if needed. Next step: if the band rides up, go down a band size. If the cups gap, go down a cup size.

Bra styles to try once you have your measurements

• Cherry On Top Bra: This underwire bra is made with sustainable and recycled materials and is part of a limited, exclusive in-house design run. If you want a structured underwire fit with a lower environmental impact, this is a good style to test your new size in.
• Jade Bamboo Bra - White: This milk white bamboo bra is designed for a luxurious feel and is part of a limited run. A bamboo fabric bra can feel softer against the skin, which is helpful if you are still adjusting to a new band size.
• Daisy Bra and Brief Set: This bra and brief set includes a Daisy Underwire Bra and Daisy Briefs, both available in multiple sizes. Buying a matching set lets you confirm your band and cup size across two pieces at once, so you can compare fit more easily.

Measuring yourself for a bra at home is a five-minute task that can change how your clothes feel all day. Start with your calculated size, try a style like an underwire bra or a bamboo bra, and adjust by one size if the fit is not quite right. Your measurements are a starting point, not a rule.