How Many kWh Does a Tankless Electric Water Heater Use?
Tankless Electric Water Heater energy cost calculator — see your exact daily, monthly, and yearly electricity cost.
US national average. Edit for your local rate.
Daily Energy Use
9.00
kWh / day
Monthly Cost
$50.84
Yearly Cost
$618.57
Tankless Electric Water Heater — Cost Breakdown
| Period | kWh Used | Cost ($) |
|---|---|---|
| Per Hour | 18.0000 | $3.3894 |
| Per Day | 9.00 | $1.69 |
| Per Month (30 days) | 270.00 | $50.84 |
| Per Year (365 days) | 3285.00 | $618.57 |
A tankless water heater running for 30 minutes uses about the same energy as a clothes dryer running for 3 full cycles.
3 Ways to Cut Your Tankless Electric Water Heater Energy Bill
- 🌱
Install low-flow fixtures (1.5 GPM showerheads) to reduce the volume of water that needs heating.
- 💡
Set the output temperature to 120°F — tankless units heat on demand, so there's no reason to set it higher and mix with cold.
- ⚡
Flush the unit with vinegar annually to remove mineral scale that insulates the heat exchanger and reduces efficiency.
Tankless water heaters use high-wattage resistance elements that activate instantly at full power with no surge beyond their rated draw.