Water Heater Size Calculator

Number of People

Number of Bathrooms

Formula

1-2 people: 30-40 gal. 3-4 people: 40-50 gal. 5+ people: 50-80 gal. Adjust for extra bathrooms.

How do I choose a water heater size?

Base it on household size: 1-2 people need 30-40 gallons, 3-4 people need 40-50 gallons, and 5+ people need 50-80 gallons.

How much hot water does a person use daily?

The average person uses about 20 gallons of hot water per day for showers, dishes, and laundry.

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