Bra Measuring Guide

Getting a correctly fitted bra is as important to a breastfeeding mother as drinking enough liquids or getting baby’s latch perfected. Poorly fitted bras can lead to issues such a blocked ducts (which can lead to mastitis).

First of all, lets just get some myth busting out of the way:

  • You CAN wear underwired bras whilst breastfeeding IF you are 100% sure you are wearing the correct size. The underwire should be flush against your chest. We do not recommend underwire until your supply has settled, however, which is usually by 4/5 months.
  • If you are currently wearing a ‘high’ band size (36+) and a ‘low’ cup size (A-D), chances are you are wearing the wrong size.
  • Just because you’ve been measured at the likes of places such as Mothercare/Debenhams/M&S or even John Lewis, doesn’t mean you are wearing the correct size.
  • A ‘D’ cup can have the same cup volume as a ‘GG’ cup. This is demonstrated below. The blocks with the same colours have the same cup volume.

Symptoms of a poorly fitted bra:

  • Riding up your back
  • 4-boob bulge
  • Neck or back pain
  • You can’t lift your arms without your bra lifting with them (and boobs falling out the bottom!)
  • ‘Armpit fat’
  • Underwire not sitting flush against your chest
  • Straps constantly loosening (and often falling off the shoulder)
  • Straps digging in and leaving marks
  • Underwire digging into your flesh

If any of this sounds familiar, or you haven’t been measured in the last year, it’s time to crack out the measuring tape!

We recommend soft crop top type tops for the first 8-12 weeks of breastfeeding.

So What Size Am I?

Go to and pop in the measurements described below into the calculator.

With clothes and bra off, measure underneath your bust and measure it so tight that you think that the tape might snap. This is your tight measurement.

Then do this again, measure tightly but still be able to get two fingers under the back. This is your snug measurement. If you are getting 2.5-3 inches above your tight then you haven’t done either measurement correctly.

Then lean over so that your boobs are dangling at 90 degrees. Measure around the nipples without squishing them. This is your leaning measurement.

Do ask in Boob Or Bust if you have any questions.

Ideally, it’s worth doing both to get the best idea what your bra size is. Alternatively, Bravissimo and Rigby and Peller have been recommended for spot on measuring!

Recommended nursing bra retailers:

  • – Offers free returns and free delivery over £75. Good prices. LOTS of sizes to pick from. Keep an eye out for Kris Line and Cake Lingerie bras!
  • Bravissimo –  Small range – good fitting guide with video. Good prices.
  • – Offers free delivery, great prices and fantastic customer service.
  • Hot Milk – dedicated nursing bra website with large selection available. Lots of pretty designs!
  • Fig Leaves – Lots of choice available. Bit more on the expensive side.
  • Molke – fun, vibrant and comfortable bras, made in Scotland.

Still stuck? Join the Boob Or Bust Facebook group for further help on bra fitting or to ask any questions!

Outfit of the Week

Discreet Bowtique
Sally Dress
From £36.00

This perfect fitting dress is made of a lovely jersey fabric with a double layer and hidden slits for feeding. In turquoise, purple, grey, black, navy blue.

Size range: 8, 10, 12, 14, 16, 18