What sizes are offered in the Helix Kids Mattress? May 16, 2023 21:23 Updated The Helix Kids Mattress is available in two sizes: Twin: 38" W x 75" L x 8” HFull: 54" W x 75" L x 8” H Related articles What is the weight limit for the Helix Kids Mattress? Does the Helix Kids Mattress include a 100 night sleep trial? How Can A Mattress with coils be rolled up? Won't that damage the bed? How hard is unboxing a Helix mattress? Do I need a mattress protector with the Helix Kids Mattress?