How much does it cost to run a water heater?
We've pre-filled a typical water heater below. Set your electricity rate and adjust the hours to match how you use yours — the cost updates instantly.
Typical power 4,000W
Usual range 3,000–5,500W
Category Laundry & water
An electric water heater is usually the second-biggest energy user in a home after heating and cooling. The elements draw several thousand watts, and although they only switch on to reheat the tank, that adds up to roughly 10–13 kWh on a normal day for a family — every day, all year.
Because it's reheating water you've used (and losing a bit of standby heat from the tank), the cost tracks your hot-water habits more than anything else.
What drives the cost of running a water heater
- Hot water used — long showers, hot laundry and the dishwasher all make it reheat.
- Tank temperature: a setpoint of 140°F costs more to hold and reheat than 120°F.
- Standby loss — an old, poorly insulated tank in a cold space leaks heat around the clock.
How to cut it
- Turn the thermostat down to 120°F — plenty hot, and it cuts both reheating and standby loss.
- Shorter and cooler showers are the biggest lever, since showers are most of the hot water.
- Insulate an old tank and the first few feet of pipe; fix any dripping hot tap.
- A heat-pump (hybrid) water heater uses a fraction of the electricity if you replace it.