How to Measure Yourself Correctly

You've got the measuring tape in hand, you've followed the steps, and the bra still feels wrong when it arrives. That's not unusual. The problem is rarely the size chart, it's usually how the measurements were taken.

This guide is a companion to Find Your Size. There, we show you how to measure. Here, we go through what tends to go wrong, why even small errors have big consequences, and how to check that your measurements actually came out right.

Quick answer: The three most common sources of error when measuring bra size are measuring over clothing, holding the tape too loosely under the bust, and rounding the measurements yourself. In Swegmark's size chart, 5 cm equals one full band size step and 2 cm equals one full cup size step. A couple of centimeters off is enough to land you in the wrong size. Measure directly against the skin or in a thin, unpadded bra, keep the tape horizontal and snug without pulling tight, write down the number in whole centimeters exactly as you read it, and let the chart handle the rounding.

Why Small Errors Have Big Consequences

The size scale is tighter than most people think.

• Band size moves in 5 cm steps. A measurement of 72 cm gives a band size of 70. A measurement of 73 cm gives a band size of 75. A single centimeter's difference, a whole step in the result.

• Cup size moves in 2 cm steps. The difference between A and B, or between D and E, is two centimeters on the bust measurement. A tape that slips down a little at the back can easily cost you a whole cup size.

• The errors compound each other. Measure too loosely under the bust and you get too large a band size, and since the cup size is calculated from the difference between the two measurements, the cup ends up too small at the same time. One mistake, two consequences. That's why the band rides up in the back at the same time as the bust spills over the edge.

This is also why it pays to remeasure, calmly and carefully, rather than guess.

Before You Measure

Five minutes of preparation makes more difference than the measuring itself.

• Use a soft fabric or vinyl measuring tape. Old fabric tapes stretch out over the years and can be off by several centimeters.

• Take off your top. Measure directly against the skin or in a thin, unpadded bra that fits well.

• Stand in front of a mirror. You need to be able to see where the tape sits at the back.

• Stand up straight, with your shoulders relaxed and your arms by your sides when you read the number.

• Measure twice if you can. If you get the same number both times, you can trust it.

The 8 Most Common Mistakes

1. You measure over your clothes

A t-shirt adds one to two centimeters. A thicker sweater, considerably more. Since the band size step is only 5 cm, that's often enough to push you up a size, with the cup shifting down to compensate.
Do this instead: measure against bare skin or in a thin bra with no padding.

2. The tape is too loose under the bust

This is the classic mistake. Many people pull the tape gently so it feels comfortable, but the band should sit snug against the body. A too-loose measurement results in a bra that's too big around and too small in the cup.
Do this instead: tighten the tape until it sits snug against your ribcage, right under your bust, without digging into the skin. You should still be able to breathe normally.

3. You pull it so tight it pinches

There's an opposite mistake too. If you pull the tape so tight that the skin bulges over it, the band size comes out too small, and the cup then comes out too big. A bra with too small a band chafes, leaves marks, and feels uncomfortable within an hour.
Do this instead: snug, not tight. The tape should stay in place when you let go, but you should be able to slide a finger underneath it.

4. The tape tilts at the back

It's hard to keep a tape horizontal behind your own back. If it dips down a couple of centimeters, the band size comes out bigger than it should. The same applies to the bust measurement, which also tends to angle upward toward the shoulders.
Do this instead: check in the mirror that the tape sits at the same height all the way around. Ask someone to help with the back if you can.

5. You measure the bust at the wrong point

The measurement should be taken straight across the fullest part of the bust. Measure too high, toward the collarbone, and the number comes out too small, giving too small a cup. Measure too low and you get the opposite effect.
Do this instead: stand up straight, let the tape run across the fullest point and rest against the bust without pressing it flat. This measurement should be looser than the band measurement.

6. You measure in a padded or shaping bra

A padded, push-up, or minimizing bra changes the shape of the bust and, with it, the bust measurement. Padding adds volume that isn't really yours, and a minimizer flattens things out. Both give you the wrong cup size.
Do this instead: measure in a thin, unpadded bra or with no bra at all. If you only have padded styles at home, it's better to measure with no bra on.

7. You round the numbers yourself

This is the quietest mistake, because it feels helpful. Many people round up "just to be safe," or shave off a centimeter to land on a neat number. The size chart is already built with ranges that do the rounding for you.
Do this instead: write down the measurement in whole centimeters, exactly as you read it. If you land between two lines, round to the nearest whole centimeter and don't add anything extra.

8. You measure at the wrong time

The body fluctuates. The bust can feel fuller in the days before your period, after a big meal, or during periods of hormonal change. Measure on a day when you're bloated and you'll get a number that doesn't hold for the rest of the month.
Do this instead: measure on a completely ordinary day, in the morning or late morning, and remeasure at another time if the number feels off.

How to Know Your Measurement Was Right

The tape gives you a starting point. The fit gives you the answer. Once the bra arrives, check the following:

• The band sits horizontal at the back and doesn't ride up when you raise your arms. If it rides up, the band size is too big.

• You can fit two fingers under the band at the back, no more.

• The cup holds the whole bust without anything spilling over the edge or gaping at the top.

• The underwire lies flat against the ribcage, between the breasts and out at the sides, without resting on breast tissue.

• The straps stay in place without you having to pull them tight. They should fine-tune the cup's position, not carry the weight.

If the measurements check out but the fit still feels wrong, it's often the style, not the size, that needs changing. Read more in Find the Right Bra Style or The Sister Size Guide.

Checklist Before You Order

• A soft, intact measuring tape

• Bare skin or a thin, unpadded bra

• A mirror in front of you

• The tape horizontal all the way around

• Snug under the bust, loose over the bust

• Whole centimeters, no rounding of your own

• Two measurements that give the same number

Once you have your measurements, move on to the size calculator and size chart.

Frequently Asked Questions

Should I wear a bra while measuring?
Yes, a thin, unpadded bra that fits well works best, and that's how Swegmark's size chart was developed. If you only have padded or shaping styles at home, it's better to measure without a bra, since padding and shaping change the bust measurement.

How tight should the tape be under my bust?
Snug against the body, but not so tight that the skin bulges over it. You should be able to breathe normally and fit one finger under the tape. Too loose is the most common mistake, and it results in both too large a band size and too small a cup.

How much does it matter if I measure over a t-shirt?
Often one to two centimeters. Since band size moves in 5 cm steps, that can be enough to shift you a whole size, and the cup is affected at the same time since it's calculated from the difference between your two measurements.

Should I round my measurements?
No, write them down in whole centimeters exactly as you read them. The size chart is built on ranges and does the rounding for you. Rounding up or down yourself is one of the most common causes of the wrong size.

My measurement falls right on the border between two sizes. What do I do?
Remeasure first, ideally at a different time. If you get the same number again, go with the smaller band size and the larger cup. The band stretches with wear, and a cup is easier to grow into than to squeeze into.

Why am I getting a different result than the size I usually buy?
Sizes differ between brands and between styles, and the body changes over time. If the result is very different from your usual size, it's worth remeasuring and checking the fit of the bra you already own. Our customer service team is happy to help you interpret your measurements.

How often should I remeasure?
About once a year, and beyond that whenever your body changes. Weight changes, pregnancy, breastfeeding, menopause, and hormonal changes all affect both band size and cup size.

Can I measure myself, or do I need help?
You can manage it yourself with a mirror. The tricky part is keeping the tape horizontal at the back, so if you have someone nearby who can check that, your measurement will be more reliable.

Do the same measurements apply to swimwear?
You use the same two measurements, underbust and bust, but swimwear has its own size chart. Take your measurements the same way, then go to the swimwear size chart.

How do I measure the right size for briefs?
Measure around the widest part of your hips, with the tape horizontal and against bare skin. The same rules apply: no measuring over clothes, and no rounding your own numbers.

Should I order more than one size?
It can be a good idea if your measurement falls close to a border, or if you're trying a new style. You simply return whatever doesn't fit.

Still unsure after remeasuring? Contact our customer service, we're happy to help you interpret your measurements.