I’m a 36B and Want to Be a 36DD. What Size Breast Implants Do I Need?

Going from a 36B to a 36DD is a three-cup jump: 36C, then 36D, then 36DD. One clinical study averaged about 138cc per cup size, which puts a rough starting point at about 400cc to 450cc per breast. Looser rules of thumb go as high as 600cc. Treat any of these numbers as a range to test, not an answer.

For your goal, that range is shakier than usual, for two reasons. A 36 band changes what a cup letter means, and DD is the cup letter that varies most from one bra brand to the next. This guide covers both, then shows how to test the fullness you want by wearing sizers at home.

How many cc does it take to go from 36B to 36DD?

Here's the three-step estimate, using the low and high ends of common per-cup figures:

Rough rule-of-thumb estimates per breast, not a conversion. Cup size after surgery depends on your anatomy, the implant and the bra you buy.

The low end comes from a clinical study that averaged about 138cc per cup size, which our A cup to D cup guide explains. The high end comes from the 150cc to 200cc per cup that many sizing guides use, including our 34A to 34C guide. Neither figure was measured on a 36 band specifically.

What a 36 band does to your cup letter

A cup letter only means something next to its band number. Bra makers use the same cup shape across a diagonal of sizes. A plastic surgery paper by Dal Cin and Jeans notes that the cup used for a 34D is the same as for a 36C and a 38B. These are often called sister sizes.

Sister sizes hold roughly the same cup volume. Exact volumes vary by brand.

That has two practical effects. Your 36B cups already hold about as much as a 34C. And a 36DD holds more than a 34DD, so a cc chart built around a 34 band can undersell what a 36 band needs.

Why 36DD is the hardest cup size to pin down

A 2025 study from Yale tested exactly your sizes. Moscarelli and colleagues fitted bras sized 36A to 36DD from seven manufacturers onto a mannequin, filled them with sizers, and measured how much each cup held. Cup volume differed significantly between brands at every size, and the bigger the cup, the bigger the difference.

The letters themselves add confusion. According to Glamorise's sizing guide, DD means the same thing in US and UK sizing. The size after it doesn't: US brands call it DDD or F, while UK brands call it E. So an E cup from a UK brand is one size bigger than your goal, not another name for it.

This is why we keep saying the same thing: decide on the look, not the letter. "I want to be a DD" gives your surgeon a label that changes from brand to brand. "I want to fill a fitted top and look full from the side, but not be the first thing people notice" tells her what you actually want.

What 450cc looks like on the same model

450cc sits at the top of the clinical 36B to 36DD estimate. Drag the slider to compare the same model without sizers and wearing 450cc external sizers in the pocket bra. Her frame may be different from yours, so watch how much fullness is added, not the cup letter.

No sizers versus 450cc external sizers. External sizing demonstration only. Not a prediction of surgical results.

For more on how this volume looks in daily life, see 450cc in everyday clothes. If you're weighing the top of the range, 400cc vs. 500cc walks through that 100cc step.

How to test 36DD fullness at home

A three-cup jump is a big change to live with, so it's worth testing over days rather than minutes in an office. Oumènta external sizers go up to 500cc. For a 36B to 36DD goal, comparing 400cc, 450cc and 500cc covers the clinical estimate and goes a step above it. If 500cc still feels too small after a few days, that's useful to tell your surgeon too.

Before you start, write down what "36DD" means to you, then score each volume against it. A simple scorecard keeps you from judging by mood on the day:

Copy this into your phone notes or print it. Score each volume on a different day.

Wear each volume for at least a full day. Our wearing routine lays out how long, and the three-outfit test covers what to put on. Take photos the same way each time, using our fair comparison photo guide, so lighting and angles don't decide for you.

Wanting a big change is common. So is wishing you'd chosen differently.

Going up three cup sizes is a bigger change than most women make, and it's easy to second-guess in either direction. In one study of 341 women, about one in four surveyed three months after augmentation said they would have preferred a different breast size. 16.7% wished they were larger and 7.3% wished they were smaller.

Sizers can't predict your surgical result or guarantee you'll be happy with your size. What they can do is help you go into your consultation knowing what you want. Bring your measured bra size, the brand you usually wear, the volume that scored best on your sheet, and your photos. Your surgeon will decide what suits your body. For the full approach, see how to choose the right breast implant size.

You can be happy with your breast augmentation and still wish you'd chosen a different size.

36B to 36DD: other questions

This article is for general education about choosing a size. It is not medical advice. Oumènta sizers are apparel worn outside the body, not medical devices, and they cannot predict surgical results. Talk with a board-certified plastic surgeon about what's right for you.

Oumènta Editorial Team • Not medically reviewed