This suit is cute but does run about 2 sizes smaller than my daughter's normal size and I used their sizing chart to hopefully get one that would fit her through the summer. She's just barely 8 and I purchased a 10 and it barely fit her. Also FYI she is under weight for her age. Tall in the 90th percentile and 48th percentile as far as her weight ratio. So no they do not run "true to size" they are cut but thin fabric and I was not at all happy with the bottoms, they did not cover enough. Sending it back and ordering a different one by the same manufacturer same sizing chart and two sizes bigger. Hopefully it will fit right this try.