Strapless Bra Size Guide

Which size to try

1. Your everyday size, provided its band is firm on the loosest hook.
2. One band down, one cup up. From 34D, that is 32DD. The cup holds the same and the band grips harder.

Take both into the fitting room. The sister size calculator gives the second size for any starting point. If your everyday band rides up at all, your strapless size will certainly be the smaller band.

How it should fit

• The band is noticeably firm and sits level all the way round. It should feel snugger than your everyday bra, without stopping you breathing deeply.
• It fastens on the loosest or middle hook when new.
• The cups contain you with no bulge over the top. Strapless cups are cut straight across, so overflow shows.
• The centre panel sits flat on your breastbone.
• The top edge lies against your skin and does not stand away.

Test it properly

Do all of these before deciding.

• Raise both arms above your head.
• Jump lightly on the spot a few times.
• Bend forward and stand up again.
• Twist from side to side.
• Sit down.

If you need to pull it up after any of these, it will not last an evening. Try the smaller band or a different construction.

Features that keep a strapless up

• Silicone grip strips along the top and bottom edges of the band and cups.
• A deep band with three, four or more hooks.
• Side boning, so the band cannot fold or collapse.
• Firm, low-stretch wings.
• Structured cups, moulded or seamed with a firm lining, that hold their shape unsupported.

Larger cup sizes

From about a DD cup, an ordinary strapless is asking a narrow band to carry a lot of weight. Look for bras designed for the job:

• Strapless bras from full-bust brands, which are built with deep bands, strong boning and proper cup construction in UK sizes up to G and beyond.
• Longline strapless bras and basques. The band extends down to the waist, anchoring on the whole torso. This is the most secure option and popular for weddings.
• Multiway bras worn with one strap, crossed straps or a halter, if the neckline allows. Even one strap adds a lot of security.

Common problems

On the day

• Skip body lotion where the band sits. Silicone grips clean, dry skin.
• Wear it at home first for an hour.
• Keep it for occasions. Silicone and firm elastic wear out faster than an everyday bra.

For specific outfits, see best bras for a wedding dress and best bras for backless dresses.

Frequently asked questions

Should I size down in the band for a strapless bra?

Often, yes. A strapless bra relies entirely on the band, so many people get a better hold from one band size down with one cup letter up, which keeps the cup volume the same. If your everyday band is already firm and correct, try your usual size first.

Why does my strapless bra keep falling down?

Nearly always because the band is too loose. Less often the cups are too small and push the bra down, or the bra has no silicone grip or side boning.

Can you wear a strapless bra with a large bust?

Yes. Choose one made for fuller cups: a deep, firm band with four or more hooks, side boning, silicone grip and seamed or firmly moulded cups. A longline or basque gives the most security.