How to choose a bra size. Bra size calculator
-
Already measured? Enter both numbers and we will work out your size. If not, the measuring steps are below.
Bra size calculatorStep 1. Find your band size
Measure directly under the bust, on bare skin, with the tape pulled firmly and after breathing out fully, so that you get the smallest possible result. Make sure the tape stays parallel to the floor. Round the number to the nearest figure divisible by 5: that is your band size. For example, 74 cm gives a band size of 75.
This is the European system used in Lithuania, and it is clear and simple. Some countries, such as Italy, France or the USA, use their own systems, which are more complicated and less logical. You will find the conversions in the table below. If you buy a bra on a non-Lithuanian website, always check which system is used there. On our site, sizes follow the European system.
Underbust measurement (cm) 63-67,5 67,5-72,5 72,5-77,5 77,5-82,5 82,5-87,5 87,5-92,5 92,5-97,5 97,5-102,5 102,5-107,5 107,5-112,5 112,5-117,5 117,5-120 Band size EU 65 70 75 80 85 90 95 100 105 110 115 120 Band size UK 30 32 34 36 38 40 42 44 46 48 50 52 Band size FR 80 85 90 95 100 105 110 115 120 125 130 135 Band size IT 0 1 2 3 4 5 6 7 8 9 10 11 Step 2. Measure your bust at the fullest point
Measure wearing a well-fitting non-padded bra. No t-shirt, blouse or any other top. Stand up straight, do not hunch. Hold the tape loosely: it should stay parallel to the floor and lie flat, but must not compress or flatten the bust.
The most common mistake when measuring at home is measuring over a t-shirt. Our own check: the same woman measured 88 cm over a close-fitting t-shirt and 92 cm without it. Four centimetres on the European scale is two cup sizes, so the result moved from A to C. Posture matters for the same reason: hunching makes the number smaller.
A second way to measure. Take the bra off, lean forward about 90 degrees so the breasts hang freely, and measure at the fullest point. Here you can pull the tape a little firmer, the way you would want a bra to support you.
What if the two measurements differ?
Calculate the size from the larger measurement, or from the average of the two. Better still: calculate with both and try on both sizes. The difference between them is not an error, it shows how mobile your breast tissue is, and that is what decides which models will suit you best.
Step 3. Find your cup size
Subtract the underbust measurement from the bust measurement. Find the resulting difference in the table below.
Examples:
Underbust 76 cm, fullest point 95 cm, difference 19 cm, size 75D
Underbust 88 cm, fullest point 106 cm, difference 18 cm, size 90DDifference (cm) 10-12 12-13,5 13,5-15,5 15,5-17,5 17,5-19,5 19,5-21,5 21,5-23,5 23,5-25,5 25,5-27 Cup size EU AA A B C D E F G H Cup size UK AA A B C D DD E F FF Cup size FR AA A B C D E F G H Cup size IT AA A B C D DD E F G Note that the smaller cup sizes are the same in every system, while the larger ones start to differ.
The larger and softer the bust, the less precise this method is. A tape measure shows nothing about depth, width or how the tissue is distributed. That is why we do not recommend relying on it alone when choosing a bra.
Would rather not do the maths?
Enter two measurements and we will work out the size for you.
Bra size calculatorIf the calculator shows 75E, it does not mean „my size is 75E“. It means „75E is where to start fitting“. In practice a particular model may fit better in 70F, 80D or another neighbouring size.
Why calculating the size is not enough
Two bras marked the same will not necessarily fit the same. Sizes differ between brands, and sometimes between models of the same brand. It depends on how firm and elastic the band is, on cup construction and depth, on wire width and shape, and on the fabrics.
You can own a 75E from one brand that fits perfectly, a 75E from another that is too small, and a third 75E that is right in the band but wrong in cup shape.
A litre of water can be poured into a tall jar or into a flat plate. Same volume, completely different shape. In the same way, two women whose number and letter match can have very differently shaped breasts. They will need different models, even though the size is the same.
How to tell whether a bra fits
The band should sit firmly but comfortably around the body and stay horizontal across the back. It should not ride up.
The breasts should sit fully inside the cups, without spilling over the edge and without being compressed. At the same time there should be no loose, wrinkled fabric in the cups.
The wires should encircle the breast tissue, not rest on it or dig in.
Straps should be adjusted comfortably, but the support comes from the band and the construction, not from them. If straps dig in or slide off, the band is usually too loose.
The best way to find the right bra is to try it on
Measuring at home and using the calculator narrow the search. Whether a particular model fits can only be seen by trying it on.
It is easier still with an experienced bra fitting consultant. They look not at centimetres but at how the band sits, where the breast tissue ends, how the wires and cups enclose it, and which construction holds best.
At SILUETA we work exactly this way: we do not look for one correct number, we help find a bra that sits well, supports comfortably and shapes beautifully.
If the calculator result surprised you, or several sizes seem equally close, that is normal. Numbers are only the beginning. What matters is how a particular bra fits you.
Written by: Vaiva Tylienė — medical doctor, certified bra fitting specialist, founder and manager of Silueta.
