Compare Water Heating Costs
This calculator shows the approximate costs of heating water for a typical family. Gallons-per-day, temperature rise, cost-per-unit, and energy factor values are all adjustable.
To use a different fuel costs and/or energy factor, type the new values into the fields and then click “Calculate” below.
- To talk with a professional about upgrading your water heating system, contact an Efficiency Maine Residential Registered Vendor.
- Your fuel prices may differ. Check up-to-date and regional pricing.
- Learn about Efficiency Maine’s heat pump water heater rebates.
kWh (Kilowatt hour) - A unit of electricity.
therm - A measure of natural gas heat energy equal to 100,000 BTUs.
LP (liquefied petroleum) - Liquefied petroleum gas. Also referred to as propane or butane gas.
Energy Factor - A measure of efficiency. An energy factor of 0.50 is 50% efficient.
Temperature Rise - The temperature difference between the cold and hot water. Typical incoming water is 50°F and is generally heated to 120°F, so the typical temperature rise is 70°F.
Gal/Day - Gallons per day of hot water used. A typical family uses 50 gallons per day.
Gal - Gallon.
This calculator is for comparison purposes only. Actual performance may vary. Default energy prices last updated: 2/13/2023.