How to Measure Your Bra Size at Home

To measure your bra size at home, take one measurement around your ribcage just under your bust for the band, and a second around the fullest part of your bust for the cup. The difference between the two points to your cup size, which you then check against the brand's own chart.

This guide gives you the steps and the common mistakes. Charts differ from brand to brand, which is why AI size recommendation for fashion stores uses each store's own chart.

What do you need?

• A soft measuring tape. A string and a ruler also work.
• A well-fitting, unpadded or lightly lined bra, or no bra
• A mirror
• A pen and paper

Measure in the same kind of bra each time. Heavily padded bras add inches to the bust reading.

How do you measure your band size?

The band is the part that holds the bra in place, so it needs a firm, level measurement.

1. Stand straight and breathe out normally.
2. Wrap the tape around your ribcage directly under your bust.
3. Keep the tape level with the floor all the way around. Check in the mirror.
4. Pull it snug but not tight. You should be able to breathe comfortably.
5. Note the number, and write down the unit.

Many brands convert this number to a band size with their own chart. Look up your number on that chart instead of assuming it.

How do you measure your bust?

The bust measurement shows how much volume the cups need to hold.

1. Stand straight with your arms relaxed.
2. Wrap the tape around the fullest part of your bust, across the nipple line.
3. Keep the tape level and light. Don't compress.
4. Note the number.

Take it twice. Measure again after a few minutes, as the second reading is often more reliable.

How do you work out your cup size?

Compare the bust measurement with the band measurement. The difference between them maps to a cup letter on most charts.

Because sizing systems differ by country and brand, don't rely on a single rule. Use the chart for the exact bra you want to buy. Some brands show cup sizes in UK letters, others in US or EU, and the letters may not match across systems.

If you are between sizes, check the fit notes. Our guide on how a bra should fit shows what to look for once you have the bra on.

What mistakes should you avoid?

• Measuring over thick clothing. It adds to the reading.
• Letting the tape slip down the back. Use a mirror.
• Pulling too tight. The band reading becomes too small.
• Measuring once. Repeat and use the more consistent number.
• Trusting one size forever. Weight, hormones and age can change your fit.

How should you check fit once the bra arrives?

A measurement is a starting point, and the bra itself is the test. Check these:

• The band sits level and doesn't ride up at the back.
• The cups hold your whole bust with no spilling at the top or sides.
• The center panel lies flat against your chest.
• The straps carry little weight. The band does most of the support.

For sport, a different cut applies. See how a sports bra should fit.

How do you record your measurements?

Write down more than the final size. A short note helps you shop with confidence next time.

• Your band and bust measurements, with the unit
• The date and the type of bra you wore
• The brand and size that fit you best
• Any brand that ran large or small for you

When you try a new brand, compare its chart with your numbers first. If the chart does not list the exact measurement ranges, look at the fit notes or reviews, or ask the store before you buy.

What if you can't measure well yourself?

Some people struggle to get a clean reading alone. A friend can help, or you can visit a shop that offers fittings.

Stores can also help. ZeDaq.ai's size recommendation uses one photo plus height, then matches the measurements to the store's chart. Unlike a tape measure, you stay dressed and don't need help. It works for tops, outerwear, dresses and bottoms, with charts the store enters itself, so confirm that a store has added a chart for the item you want.

Brands that make clothes to order often ask for fuller measurements. Size recommendation for made-to-measure brands explains how they handle it.

Many stores weigh whether to use charts or try-on. Virtual try-on versus size charts compares them.

FAQs

Should I measure with or without a bra?

Either works if the bra is thin and fits closely. Don't measure in a heavily padded or push-up bra.

How often should I measure?

Check once or twice a year, or after a big change in weight or after pregnancy. Bodies change.

Are bra sizes the same across brands?

No. Each brand cuts differently, and countries use different systems. Always use the brand's own chart.

What if my two sides are different sizes?

This is common. Choose the size that fits the larger side, and use removable pads or adjust the strap on the other side.