There are many models with different capacities. To determine the right water heater for you, consider your budget, the size of your home, and your family’s needs. Sizes can range from 30 gallons up to 100 gallons. If you are running out of hot water often and the water heater is in good condition, then you may need to get a water heater with a higher capacity. However, if you are not using a lot of hot water, then a smaller tank will be more budget-friendly and environmentally friendly.