Size 34M Swimwear
Also labeled UK 34J and EU 75M
34M swimwear pairs a mid-range band with a very full, projected cup, so the band has to stay firm while the cups hold real depth. Start with your usual bra size, then check how the suit feels once it is wet. Our Swimwear Size Chart shows the matching UK and EU labels.
Sort by
2 products
Checking the Band on a 34M Swimsuit
If the 34 band only feels secure when the straps are pulled tight, the band is doing too little of the work. Check the band dry and again after a few minutes in the water, since wet fabric can feel noticeably looser. Before you tighten the straps, make sure the band is level from front to back.
Sit down in the suit and lean forward. If a very full, projected cup lifts out of the cups or the band peels away at the back, the band needs to be firmer.
Cup Coverage for a 34M Bust
Give an M cup a moment after you put it on, since tissue can take a little settling to sit fully inside. Smooth the fabric over each cup after you settle in, and check for wrinkles that suggest the shape does not match yours. If the cups wrinkle but also press in one spot, the shape may be wrong rather than the size.
In UK sizing, look for 34J. A UK J is a US M, while a US J is three cups smaller.
Choosing Coverage for a 34M Bust
Coverage is a personal choice, but the edge of the cup should always lie flat. If a low neckline leaves you spilling at the top, the cup may be too shallow for 34M rather than the wrong letter. Try a fuller coverage cut before changing your size.
Need a bra in the same size? See our 34M bras.
Frequently Asked Questions About Size 34M Swimwear
How does 34M swimwear convert to UK and EU sizes?
Look for UK 34J or EU 75M, keeping in mind that a US J is three cups smaller than this. Follow the system printed on each label.
How do I know if a 34M one-piece is too short in the torso?
The straps dig into your shoulders, the leg openings pull up, and the suit feels like it is dragging down. With a very full, projected cup, the bust uses extra length, so check the torso fit while sitting as well as standing.
Is a tankini a good option for a 34M bust?
Yes, a tankini can help when one-piece torso length is the problem, because the top and bottom are separate. The top still needs cups deep enough for 34M and a band that stays firm, which matters even more on a mid-range band.
What should I do if 34M swim cups gap at the top?
Settle your bust into each cup first, then check again. If the gap stays, the cup shape may not suit you or the cup may be a little deep for a mid-range band, so compare a different coverage before changing size.
What does it mean if a 34M swim cup edge cuts in?
It usually means the cup is too shallow for your depth, even if the letter is right. With a very full, projected cup, look for cups with more depth or coverage rather than a tighter band.
Should the straps hold up 34M swimwear?
No. The band and the body of the suit should carry most of the support, and the straps only steady it. If you need tight straps to feel secure in 34M, check the band first.