Water Heater Cost Calculator
Estimate monthly and annual costs to run your water heater based on usage, efficiency, and energy rates.
Monthly Cost
$9.92
Monthly Cost vs Hot Water Usage
Water Heater Operating Cost
Water heating is the second largest energy expense in most homes, accounting for 14-18% of utility bills.
Formula
Daily BTU = Gallons/Day x 8.33 (lbs/gal) x Temp Rise (°F)
Daily Therms = Daily BTU / 100,000 / Efficiency
Monthly Cost = Daily Therms x 30.44 x Cost per Therm
8.33 is the weight of one gallon of water in pounds. One BTU raises one pound of water by 1°F.
Example Calculation
50 gallons/day, 60°F temperature rise, 92% efficient gas heater at $1.20/therm.
- 01Daily BTU = 50 x 8.33 x 60 = 24,990 BTU
- 02Daily therms = 24,990 / 100,000 / 0.92 = 0.272 therms
- 03Monthly cost = 0.272 x 30.44 x $1.20 = $9.93
- 04Annual cost = 0.272 x 365 x $1.20 = $119.07
Frequently Asked Questions
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