Bra Size Calculator

ThirdLove Size Chart & Half Cup Guide

Decode half cups, fit quiz results, and international conversions to build your best ThirdLove bra drawer.

Calculate My SizeDownload Half-Cup Matrix

Core Conversion Table

Use this quick conversion chart when shopping internationally or comparing sizes from other brands. Half cups are indicated with “½”.

USUKEUNotes
32B32B70BStarting size for many fit quiz results.
34C34C75CAligns with 24/7 Classic T-Shirt Bra.
34C½34C (half cup)75C+Half-cup adds subtle depth for gaping cups.
36D36D80DFull coverage and wireless styles frequently use this size.
36D½36D (half cup)80D+Bridge size between D and DD without changing band.

Understanding ThirdLove’s Fit Quiz

ThirdLove’s quiz uses your feedback to recommend sizes. Use these tips to make results even more accurate.

  • Take the quiz with your current best-fitting bra. Be honest about strap slip, gaping, or digging.
  • If the quiz recommends a half cup, note whether you feel more space on top or at the sides.
  • Use your measurement difference (bust minus band) to confirm the suggested cup size.
  • Record your quiz results and compare them with calculator outputs to spot patterns.

Style Fit Notes

24/7 Classic T-Shirt Bra

True to size for most; memory foam hugs the body without gaping. Half cups are popular here.

Lace Balconette

Runs slightly shallow; size up in the cup or try a half cup if you experience spillage.

Flex Back Wireless

Wireless comfort with structured band. Size based on bust measurement and consider half cups if in between.

Kinetic Impact Sports Bra

High-impact support with adjustable straps. Use the workout fit checklist to double-check support.

Helpful Resources

Smooth out cup gaping between half cupsStay supported during workouts with hybrid brasCompare ThirdLove sizes with international charts

Frequently Asked Questions

What is a ThirdLove half cup?

Half cups add about one-third cup volume. They are perfect if your usual cup gaps slightly or you want a custom-like fit without changing the band.

Do ThirdLove bras run true to size?

Bands run true to size, while cups can feel forgiving due to memory foam. If cups gap, try a half cup down; if they compress, try a half cup up or a full cup increase.

How do I convert ThirdLove sizes internationally?

Use the conversion table below or download the matrix. For example, US 34C½ ≈ EU 75C+ and sits between 34C and 34D in UK sizing.