Here are charts to show you the sister sizes and bra equivalents for size 38, 40, and 42.
38
| Down | Current | Up |
| 36A | 38AA | 40AAA |
| 36B | 38A | 40AA |
| 36C | 38B | 40A |
| 36D | 38C | 40B |
| 36DD | 38D | 40C |
| 36DDD/36E | 38DD | 40D |
| 36F | 38DDD | 40DD |
| 36F | 38E | 40DD |
| 36FF | 38F | 40E |
| 36G | 38FF | 40F |
| 36GG | 38G | 40FF |
| 36H | 38GG | 40G |
| 36HH | 38H | 40GG |
| 36I | 38HH | 40H |
| 36J | 38I | 40HH |
| 36JJ | 38J | 40I |
| 36K | 38JJ | 40J |
| 36KK | 38K | 40JJ |
| 36L | 38KK | 40K |
| 36M | 38L | 40KK |
| 36N | 38M | 40L |
| 38N | 40M | |
Are you a 38A? Here are options you can try
Size up to a 40AA: A more oversized fit than the 38A but with the same cup.
Go down to a 36B: A smaller fit than the 38A, but with the same cup.
Is your 38B not giving you the same comfort?
Try a 40A: If a 38B is too tight, 40A will be a more relaxed fit with the same cup.
Go down to a 36C: The same cup as a 38B but is more hugging than a 38B.
Not happy with your 38C fitting?
Size up to a 40C: Within the same cup, it offers 2 inches of more freedom than a 38C
Go down to a 36D: Within the same cup, it gives 2 inches more support by being tight around your body.
Given your 38D isn’t doing good for you.
Size up to a 40C: More relaxed around the torso, but the same cup as a 38D
Go down to a 36DD: If a 38D were barely hanging on, 36DD would give more support within the same cup.
Is a 38DD too uncomfortable?
Try a 40D: If a 38DD is too tight, you will be more at ease wearing a 40D.
Go down to a 36DDD/36E: Closer-fitting band around your torso with the comfort of the cups, which remain the same as 38DD
Are you a 38DDD? Here are your alternatives
Try a 40DD: For a bra that’s looser than a 38DDD but offers the same cup.
Go down to 36F: For a bra that’s tighter than a 38DDD but within the same cup.
38F doesn’t work for you?
Size up to a 40E: If a 38F bra is too tight for you, but the cup is accurate.
Go down to a 36FF: If a 38F bra is slightly hanging on you, but the cup is perfect.
If you wear a 38G, for a better you can
Size up to a 40FF: Perfect if a 38G is too tight around your frame.
Go down to a 36GG: Ideal if a 38G is too loose around your frame, but it is the perfect cup for you.
40
| Down | Current | Up |
| 38A | 40AA | 42AAA |
| 38B | 40A | 42AA |
| 38C | 40B | 42A |
| 38D | 40C | 42B |
| 38DD | 40D | 42C |
| 38DDD/38E | 40DD | 42D |
| 38F | 40DDD | 42DD |
| 38F | 40E | 42DD |
| 38FF | 40F | 42E |
| 38G | 40FF | 42F |
| 38GG | 40G | 42FF |
| 38H | 40GG | 42G |
| 38HH | 40H | 42GG |
| 38I | 40HH | 42H |
| 38J | 40I | 42HH |
| 38JJ | 40J | 42I |
| 38K | 40JJ | 42J |
| 38KK | 40K | 42JJ |
| 38L | 40KK | 42K |
| 38M | 40L | 42KK |
| 38N | 40M | 42L |
| 40N | 42M |
If your 40B isn’t satisfactory
Try a 42A: For an extended band length but same cup comfort.
Go down to a 38C: For someone with a narrow body frame but needs the same comfort as a 40B.
A 40D can feel uncomfortable to some.
Try a 42C: A 42C is great for people who feel grown out of their 40D bra but not its cup.
Go down to a 38DD: A notable improvement for somebody who finds a 40D too big for them, but its cup is a great fit.
A 40DD isn’t your ideal fit?
Try a 42D: The band of a 42D is larger than a 40DD, while the cup is not.
Go down to a 38DDD/38E: For petite people who’d like a more snug fit of the 40DD.
If you’re a 40DDD but not happy with it
Try a 42DD: A 42DD will give you more room around your body than a 40DDD if you need it.
Go down to 38F: A 38F will provide a more compact fit than a 40DDD with the same comfort of the cups.
If 40H isn’t doing you justice, then:
Try a 42GG: More comfortable if a 40H is giving too much compression to your body.
Go down to a 38HH: Great if the 40H isn’t giving as much compression as it should to give ideal support.
Best brands
When it comes to the best brands, here are some of our recommendations:
- Calvin Klein
- Hanky Panky
- ThirdLove
- Victoria’s Secret
- Cuup
When it comes to sports bras, these are our brand recommendations:
- Nike
- Lululemon
- Girlfriend Collective
42
| Down | Current | Up |
| 40A | 42AA | 44AAA |
| 40B | 42A | 44AA |
| 40C | 42B | 44A |
| 40D | 42C | 44B |
| 40DD | 42D | 44C |
| 40DDD/40E | 42DD | 44D |
| 40F | 42DDD | 44DD |
| 40F | 42E | 44DD |
| 40FF | 42F | 44E |
| 40G | 42FF | 44F |
| 40GG | 42G | 44FF |
| 40H | 42GG | 44G |
| 40HH | 42H | 44GG |
| 40I | 42HH | 44H |
| 40J | 42I | 44HH |
| 40JJ | 42J | 44I |
| 40K | 42JJ | 44J |
| 40KK | 42K | 44JJ |
| 40L | 42KK | 44K |
| 40M | 42L | 44KK |
| 40N | 42M | 44L |
| 42N | 44M | |
42B? but not sure if it’s the correct fit for you?
Try a 44A: A decent difference in circumference of a 42B with the same cup.
Go down to a 40D: A significant decrease in circumference from a 42B but with the same cup.
Sure, of the 42C cup but not the band?
Try a 44B: Giving you the comfort of a 42B with the extended band.
Go down to 40D: It provides an easy transition from a 42C with a more figure-hugging fit.
If the 42D isn’t right for you
Try a 44C: Providing you more room between the bra and your body than 42D, without a change in the cup.
Go down to a 40DD: The bra hugs you tighter than a 42D with the same comfort.
Is a 42DDD rather uncomfortable for you?
Try a 44DD: Offering you a slight breather than a 42DDD, which might have been too tight.
Go down to a 40F: Supporting you a little extra with its smaller band.
Sure, of 42F, but not the band?
Try a 44E: Same cups but an overall bigger bra for utmost comfort.
Go down to 40FF: For somebody who’s too petite for a 42F but requires the same comfort.
Is your 42G not as comfortable as you’d like?
Try a 44FF: If you feel a 42G offers the ideal cup but digs into your skin.
Go down to 40GG: If you feel 42G is too limp on you.
Best places to buy them
If you’re looking for a place to buy them, here’s a list of places we suggest:
- Amazon
- Soma
- Knix
- Nordstrom
- Bare necessities
