Most homes have a water heater that holds between 40 and 60 gallons. Larger tanks are typically used in homes with a hot tub or other hot water requirements. Alternatively, you can follow one of the experts’ rules:
1. 30-40 gallons for 1 to 2 people
2. 40-50 gallons for 2 to 3 people
3. 50-60 gallons for 3 to 4 people
4. For groups of 5 or more people: 60-80 gallons