A well-fitting J cup bra should feel secure, supportive and comfortable throughout the day.
Start with the band. It should fit firmly around your body and sit level across your back. If it keeps riding up, it may be too loose.
Your breasts should sit comfortably inside the cups without spilling over the edges. There shouldn't be noticeable gaping, wrinkling or uncomfortable pressure.
Wearing an underwired bra? The wires should surround your breast tissue without resting directly on it. They shouldn't dig into your underarms either.
Your straps should stay comfortably in place without digging into your shoulders. Remember, most of your bra's support should come from the band.
For J cup breasts, getting the right band and cup combination is especially important.
A 10J and a 16J have different cup volumes, despite sharing the same cup letter.
Different brands and styles can also fit differently.
Unsure about your size? Visit our Determine Your Size guide for helpful fitting advice.