My 7.5 fits size 10. She’s 56 pounds and is 49-50 inches. This is the regular Speedo swimsuit. Online reviews said size up and glad we did.

Does your DD have friends who swim who might have suits she can try on for size?

Strongly suggest you go to a store. I have used the Speedo sizing tool on their website before, and gotten sizes that are way too small. You cannot just go from height and weight, because torso length and bust size is important, too.

If you are going to order online, use their sizing tool, but also order the sizes on either size of what it recommends. Try them all on, keep the one that fits, and return the others.

Anonymous wrote:

Anonymous wrote:My slim daughter who wears a size 8 or 10 in clothing wears a size 24 suit, but I think it might be getting a little short for her. She's 59 inches tall and 80 pounds.

(For the person here who is going to wonder. Yes, her pants are too short, but size 12 is way too wide.)

My muscular almost seven year old that is not yet a 6x clothing size also wears a 24. I would probably start a little higher for a 10 year old unless very petite. Here is the Speedo kids size chart: https://us.speedo.com/size-charts.list

Note the elite sizes are different but our summer and winter swim dont use the kids elite suits in this age bracket.

Anonymous wrote:My slim daughter who wears a size 8 or 10 in clothing wears a size 24 suit, but I think it might be getting a little short for her. She's 59 inches tall and 80 pounds.

(For the person here who is going to wonder. Yes, her pants are too short, but size 12 is way too wide.)

My muscular almost seven year old that is not yet a 6x clothing size also wears a 24. I would probably start a little higher for a 10 year old unless very petite. Here is the Speedo kids size chart: https://us.speedo.com/size-charts.list

My 12yo wears a 26 training suit so I’d imagine your 10yo would probably wear a 24 (which is what she wore at age 10-11)