Looking for the best bras for 40A? A UK 40A combines a 40 band with an A cup. This size is available in a range of bra constructions including plunge, T-shirt, padded, balconette, strapless, multiway and non-wired styles.
The best bras for 40A will depend on the coverage, neckline and cup construction you prefer. T-shirt and padded bras provide a shaped cup, while plunge, balconette, strapless and non-wired designs offer different combinations of coverage and construction.
Before buying a 40A bra, it can help to check the equivalent international sizes, nearby sister sizes and visual size comparison. The quick tools on this page show how 40A compares across different sizing systems and related UK bra sizes.
You can confirm your starting size with our Bra Size Calculator, check fit problems in our Bra Fitting Advice, or compare brand labels using the Bra Size Converter.
For more detail on this cup size, see our A Cup Bras Guide, How Big Are A Cups?, and A vs B vs C Cup Size Comparison.
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When looking for the best bras for 40A, comparing different bra constructions can help narrow down the options. The three bras below include styles from Naturana and Triumph, giving you different starting points when comparing coverage, shaping and design.
Top Picks at a Glance
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Quick sizing reminder for 40A:
The Naturana Cotton Wireless Bra, Triumph Amourette WHP Lace Bra and Triumph Modern Soft with Cotton Bra use different constructions, giving you several options to compare when choosing the best bras for 40A.
The Naturana is a cotton wireless style, the Triumph Amourette WHP is a padded underwired lace bra, and the Triumph Modern Soft with Cotton is a smooth wireless style with moulded, unpadded cups. Check the individual product descriptions for details of padding, cup shape, coverage and sizing before ordering.
If you need to compare equivalent sizes between different sizing systems, use our Bra Size Converter.
Recheck your measurements using the Bra Size Calculator and review band, wire and cup positioning in our Bra Fitting Advice.
When trying a 40A bra, check the band, cups, wires and straps together rather than judging the fit from the cup letter alone.
If one or more of these points does not look or feel right, use our Bra Fitting Advice for more detailed troubleshooting.
The best bras for 40A are available across several constructions, including wired, padded, moulded, plunge, balconette, T-shirt, strapless and non-wired styles. The most suitable option will depend on the coverage, neckline and cup construction you prefer.
Wired bras use an underwire beneath the cups to help define the cup shape and provide structure. The Triumph Amourette WHP Lace Bra included in our recommendations above is one example of an underwired construction available in 40A.
Padded bras include additional material within the cups and can vary from lightly padded designs to more structured constructions. The Triumph Amourette WHP Lace Bra included above is one example of a padded 40A style.
Moulded and T-shirt bras use pre-shaped cups and are commonly designed to create a smoother outline beneath clothing. Some moulded cups are made from thin shaped fabric, while others use firmer materials that retain more of their shape when the bra is not being worn. The Triumph Modern Soft with Cotton Bra included above is one example of a moulded, unpadded wireless 40A style.
Plunge bras have a lower centre front for lower necklines, while balconette bras generally have a lower, more horizontal cup line with wider-set straps. Both constructions are available in 40A, depending on the brand and collection.
Strapless bras are designed for clothing where standard shoulder straps would be visible. Individual 40A strapless styles can vary in cup shape, padding, coverage and overall construction.
Non-wired bras provide shaping and support without an underwire. The Naturana Cotton Wireless Bra and Triumph Modern Soft with Cotton Bra included in our recommendations above are two examples of wireless 40A styles.
A 40A combines a 40 band with an A cup. Bra cup letters cannot be considered independently from the band because cup volume changes as the band measurement changes.
In the UK cup sequence, this part of the progression runs: AA → A → B → C → D → DD → E. This places A immediately above AA and immediately below B.
Remember that bra size combines band size and cup size. A 40A has less overall cup volume than a 44A even though both sizes use the same A cup letter.
The closest sister sizes to 40A are 38B and 42AA. These sizes have similar cup volume but use different band measurements. You can learn more in our Bra Sister Sizes Explained guide .
The appearance of a 40A can vary because breast shape, tissue distribution, torso proportions and bra construction all affect how the same bra size looks.
Because bra sizing combines both band size and cup size, an A cup does not represent one fixed breast volume. For example, a 40A has a smaller overall cup volume than a 44A even though the cup letter is the same.
For visual examples across different A-cup band sizes, visit our How Big Are A Cups? guide.
You can also use the UK Bra Size Visual Comparison Tool to compare 40A with other manufactured UK bra sizes.
Bra size is relative rather than a standalone description of bust size. A 40A combines a 40 band and an A cup, and its overall cup volume differs from A cups on smaller or larger bands.
The closest sister sizes to 40A are 38B and 42AA. These sizes have similar cup volume but use different band measurements.
Bra sizing systems can vary between brands and countries. Use our Bra Size Converter and check the individual brand's sizing information before ordering.
Yes. Non-wired bras are available in 40A, although the number of styles and individual products varies between retailers and collections.
Depending on the retailer and collection, 40A is available in styles including wired, padded, moulded, T-shirt, plunge, balconette, strapless and non-wired bras.
Compare 40A with the same cup letter on nearby band sizes using the A-cup buying guides below.
Browse our Best Bras by Size directory to explore buying guides for all 220 currently manufactured UK bra sizes. Find your exact band-and-cup size or discover other published buying guides across the complete UK size range.
A well-fitting 40A should have a secure, level band and cups that sit smoothly against the breast tissue without gaping, wrinkling or overflow. In an underwired bra, the wires should sit around the breast tissue and the centre gore should lie against the sternum where the design allows.
Use the recommendations above as a starting point when choosing the best bras for 40A, then check the product's sizing system, construction and current size availability before ordering.
Need help confirming your size? Use the Bra Size Calculator, check equivalent-volume sizes with the Bra Sister Size Calculator, and follow our Bra Fitting Advice.
You can also compare sizing systems using the Bra Size Converter or compare 40A visually with other sizes using the UK Bra Size Visual Comparison Tool.
