Energy Bill Math

Hot water

Electric Water Heater Cost Calculator

Estimate the monthly and yearly electricity cost of an electric tank water heater from its power and daily runtime.

watts

Use the nameplate, manual, energy label, or a plug-in power meter.

hours
days
$/kWh

Find the all-in rate on your bill, or divide bill cost by total kWh.

Your estimate

Estimated annual cost

$837.68

Average monthly cost

$69.81

Cost on a day it runs

$2.30

Energy on a day it runs

13.50 kWh

A tank heater cycles rather than drawing full power continuously. Enter an estimated total heating-element runtime, not simply the hours hot water is available.

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Calculation method

How this estimate is calculated

Annual cost = (element watts ÷ 1,000) × element runtime per day × days used × rate
U.S. Department of Energy: Water Heating

Important assumptions

What can change the result

  • Runtime is the total time the heating element draws power.
  • Standby loss is reflected only if included in the runtime estimate.
  • Incoming water temperature, tank setpoint, insulation, and household usage are not modeled separately.

For the most useful estimate, use measurements from a plug-in energy monitor, connected charger, vehicle dashboard, or product energy label whenever available.

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