How to Measure for Mastectomy & Front-Fastening Bras | UK Guide


At Orchid Fashion Boutique, we believe every woman deserves a bra that feels like a second skin. Whether you are looking for high-impact sports support, a gentle post-surgery fit, or the ease of a Gemm front-fastening bra, a great fit starts with accurate measurements.

Follow our simple 3-step guide to find your true size from the comfort of your home.

Step 1: Measure Your Band Size (Underbust)

Wear your best-fitting non-wired bra (or go braless). Wrap a soft tape measure around your ribcage, directly under your bust where the band usually sits.

  • Ensure the tape is firm and level all the way around your back.

  • The Measurement: If you get an even number, that is your band size. If you get an odd number, round up to the next even number (e.g., 33 inches becomes a 34 band).

Step 2: Measure Your Cup Size (Bust)

Wrap the tape measure around the fullest part of your bust.

  • Do not pull the tape tight; it should rest gently against your skin.

  • Keep the tape level across your shoulder blades.

  • The Measurement: Note down this number in inches.

How to measure bra size for front fastening and mastectomy bras.

Step 3: Calculate Your Fit

To find your cup size, calculate the difference between your Bust Measurement and your Band Size.

Difference in Inches Cup Size
Less than 1 inch AA
1 inch A
2 inches B
3 inches C
4 inches D
5 inches DD (E)
6 inches E (F)

Example: If your band is 36 and your bust is 39, the 3-inch difference means you are a 36C.

Fitting Guides for Your Specific Needs

1. Front-Fastening & Gemm Bras

Because our Gemm comfort bras are often made of high-stretch cotton and are non-wired, they are very forgiving.

  • The Back Check: The back of the bra should sit level with the front. If it arches up, your band is too big.

  • Accessibility: Ensure you can easily operate the front hooks or zipper without excessive straining.

2. Mastectomy & Post-Surgery Bras

Fitting a post-surgery bra requires extra care and empathy.

  • Sensitivity: Your skin may be tender. Choose soft cotton linings and ensure the underband sits below any scar tissue without rubbing.

  • Prosthesis Check: If you wear a prosthesis, ensure the pocket is secure and the breast form sits naturally against your chest wall without a gap at the top.

  • Wait Time: We recommend waiting at least 6–8 weeks post-surgery before measuring for a permanent bra to allow swelling to subside.

3. High-Impact Sports Bras

A sports bra should feel tighter than an everyday bra to prevent movement.

  • The Bounce Test: Jump in place! If there is significant movement, you likely need a smaller cup or a more structured "encapsulation" style.

  • The Strap Rule: You should be able to fit two fingers comfortably under the shoulder straps. If they dig in, they are too tight; if they slip, they are too loose.

5 Signs Your Bra Doesn't Fit

If you notice any of the following, it’s time to resize:

  1. Spillage: Your breasts are overflowing over the top or sides of the cups (Cup is too small).

  2. Gaping: There is space between your breast and the cup (Cup is too large).

  3. Slipping Straps: You are constantly pulling your straps back up (Band is likely too big, or straps need adjusting).

  4. Riding Up: The back of the bra is creeping up toward your neck (Band is too big).

  5. Digging In: The band or straps leave painful red marks at the end of the day (Band/Straps are too tight).

 

  • How should a front-fastening bra fit? (Answer: It should sit level across the back and be easy to fasten without straining your shoulders.)

  • When should I measure for a mastectomy bra? (Answer: We recommend waiting 6–8 weeks post-surgery to allow swelling to subside for the most accurate fit.)

  • Does Gemm bra sizing run small? (Answer: Gemm bras are designed with soft, high-stretch cotton; if you are between band sizes, we generally recommend rounding up for maximum comfort.)