Wacoal vs ThirdLove
Two brands, two ways of grading a size. Here is how Wacoal and ThirdLove differ in system, range and fit, and which one to choose for your shape and your problem.
Wacoal or ThirdLove, in short
Wacoal and ThirdLove both label in US sizing. Wacoal runs true to size in the band and true in the cup with average wires; ThirdLove runs true to size in the band, grades generous in the cup, average wires. Range: Wacoal 30–46 / A–H; ThirdLove 30–48 / AA–H. Convert your measured size into each and let fit decide.
Your measured size in both
Same body, two labels. Each result is your US size converted into the brand's system, then adjusted for how that brand grades. Same system, so the label matches: the fit adjustment is the difference.
Wacoal vs ThirdLove at a glance
| Wacoal | ThirdLove | |
|---|---|---|
| Sizing system | United States | United States |
| Bands | 30–46 | 30–48 |
| Cups | A–H (some styles to I) | AA–H (I in select bands), plus half-cup sizes A½–E½ on 30–40 bands |
| Band grading | true to size | true to size |
| Cup grading | true | grades generous |
| Wire width | average | average |
| Straps | Standard; sport line uses wide, cushioned straps | Standard, adjustable front |
| Alpha sizes | No | No |
| Tier | Premium | Mid-to-premium |
| Origin | Japan / US | US |
| Signature line | Awareness: the flagship full-figure underwire and wireless line, cups to H | 24/7 Classic T-Shirt: memory-foam contour, the flagship, in half cups |
Which to try for your breast shape
| Shape | Wacoal | ThirdLove |
|---|---|---|
| Full on bottom | Basic Beauty contour, Halo Lace | 24/7 Classic Demi |
| Full on top | Awareness full cup | 24/7 Classic Full Coverage |
| Shallow | Basic Beauty, wireless Awareness | 24/7 Classic Wireless |
| Projected | Halo Lace, seamed Awareness | 24/7 Classic T-Shirt in a half cup up |
| Wide-set | Retro Chic full-figure | 24/7 Plunge |
Not sure of your shape? Use the shape finder.
Choose Wacoal or ThirdLove?
- a first accurate size: the label matches the measurement
- contour t-shirt bras that don't gape or spill
- cups usually feel small on you elsewhere
- between two cup sizes
- memory-foam contour without gaping
Both are right at the same measurement. The label differs by system and the fit by grading: start from your measured size, convert into each, and let the five fit checks decide.
What each brand is known for
| Wacoal | ThirdLove | |
|---|---|---|
| Line 1 | Awareness: the flagship full-figure underwire and wireless line, cups to H | 24/7 Classic T-Shirt: memory-foam contour, the flagship, in half cups |
| Line 2 | Basic Beauty: contour t-shirt bra, one of the most consistent molded fits in US sizing | 24/7 Classic Wireless: wireless contour |
| Line 3 | Halo Lace: seamless lace underwire in a broad range | Classic Strapless (runs tight in the band) size the band up |
| Line 4 | Sport: high-impact underwire sport bras graded in bra sizes, not S/M/L | Sport: bra-sized sport |
Wacoal vs ThirdLove: answered
Is Wacoal the same size as ThirdLove?
Same notation (US), different grading. Wacoal: Bands run true to size: start with your measured band on the loosest hook. ThirdLove: Bands run true to size: start with your measured band on the loosest hook.
Which runs smaller, Wacoal or ThirdLove?
Wacoal. Cups grade true to the measured difference. ThirdLove (Cups grade generous) try your measured cup and one down.
Which is better for a large bust, Wacoal or ThirdLove?
Wacoal runs to A–H on bands 30–46; ThirdLove to AA–H on 30–48. The one whose range covers your size (in its own system) and whose wire width suits your root.
Which is better for a small bust?
Whichever grades true or small at A–C: Wacoal cups true, ThirdLove cups grades generous. Small bands need the brand whose range starts lower: 30 vs 30.
Can I use my Wacoal size at ThirdLove?
Convert first (same system, so the label carries), then adjust: ThirdLove bands run true to size and cups grades generous relative to true. The calculator above does both.
Do Wacoal and ThirdLove fit the same breast shapes?
Not identically. Full on bottom: Wacoal Basic Beauty contour, Halo Lace vs ThirdLove 24/7 Classic Demi; Full on top: Wacoal Awareness full cup vs ThirdLove 24/7 Classic Full Coverage; Shallow: Wacoal Basic Beauty, wireless Awareness vs ThirdLove 24/7 Classic Wireless.
Opens HauteFlair’s own hub page; use your measured size there. HauteFlair is owned by the same company as Brasize.ai; that relationship never changes the sizing math, charts, or fit advice on this page. How this site makes money.