Water Heater Running Cost Calculator
Typical draw about 4000 W. Enter your hours and rate to estimate the monthly and yearly running cost.
WattCost runs every calculation in your browser — your usage and rates never leave this page.Try: Power (watts)=4000, Hours per day=3, Days per month=30, Electricity rate=0.15 → 360.00 kWh, $54.00, $648.00
How to use
Enter the wattage (pre-filled to about 4000 W, the typical draw for a Water Heater), set how many hours per day it runs, and add your electricity rate. WattCost multiplies watts ÷ 1000 × hours × days to get kWh, then multiplies by your rate for the cost.
Lower the tank to 120°F (49°C); each 10°F lower cuts standby loss.
FAQ
How much does it cost to run a Water Heater per month?
At about 4000 W, with 3 hours a day at $0.15/kWh, a Water Heater costs roughly $54.00 per month. Your real number depends on how many hours you use it and your local rate — enter your own figures for an exact estimate.
Does a Water Heater use power when it is off?
Most devices draw a small standby load. Unplug the Water Heater or put it on a switched outlet to stop the trickle when it is not in use.
How can I lower my Water Heater running cost?
Lower the tank to 120°F (49°C); each 10°F lower cuts standby loss. You can also shop your electricity rate — even a small drop per kWh lowers every appliance on this site.