All three steamers are able to accommodate 20 Quart; two layers can hold 14 quart, and one layer can hold 7 quart. After adding water to the bottom tank, you can freely choose one, two or three steamers on the water tank based on the quantity of food you want to steam. Capacity for 3 Tiers: 20 Quart; Capacity for 2 Tiers: 14 Quart; Capacity for 1 Tier: 7 Quart