How much does it cost to run a electric tankless water heater?
A typical electric tankless water heater draws about 5500 watts. Used 2 hours a day, that works out to roughly $1.87 per day, $56.88 per month, and $682.55 per year on an average electricity rate of 17¢ per kWh. Tankless units heat water on-demand and consume significant power during operation but avoid standby losses.
Electric Tankless Water Heater running cost calculator
- Per day
- $1.87
- Per month
- $56.88
- Per year
- $682.55
- CO₂ / year
- 1606 kg
Based on 4015 kWh per year. Adjust the price per kWh to match your latest electricity bill for an exact figure.
The number that matters most is your own electricity rate. Rates range from under 11¢ per kWh in some regions to over 30¢ in others, so the same electric tankless water heater can cost two or three times as much depending on where you live. Enter your exact rate in the calculator above to get a figure tailored to your bill.
Heating appliances like the electric tankless water heater are usually seasonal, so your real annual cost depends heavily on your climate and how many months you run it. The figures here assume average year-round use — if you only switch it on during the coldest part of the year, scale the monthly cost by the number of months you actually use it.
At 5500 watts, the electric tankless water heater is a high-draw appliance — the kind that can briefly become the single biggest load in your home while it runs. On a time-of-use tariff, shifting it to off-peak hours is often the easiest way to cut its cost without using it any less.
Over a full year this electric tankless water heater uses about 4015 kWh of electricity and is responsible for roughly 1606 kg of CO₂ emissions on an average grid. Because it runs more or less year-round, even a small reduction in daily use carries straight through to a lower annual total.
To put the draw in everyday terms, one hour of running this electric tankless water heater uses about as much electricity as charging a smartphone 458 times. It is a rough comparison, but it makes an abstract wattage figure easier to picture.
If this electric tankless water heater is one you use daily, even small efficiency gains compound. Cutting its usage or wattage by 20% would save around $136.51 every year — money that an efficient replacement can recover over its lifetime.
Frequently asked questions
- How much does it cost to run a electric tankless water heater per hour?
- At 5500 watts and a 17¢/kWh rate, a electric tankless water heater costs about $0.94 per hour to run.
- How much electricity does a electric tankless water heater use per month?
- Running 2 hours a day, a electric tankless water heater uses roughly 334.6 kWh per month, costing about $56.88.
- How many kWh does a electric tankless water heater use per year?
- Used 2 hours a day for 365 days a year, a electric tankless water heater consumes about 4015 kWh annually — that is the figure your electricity rate is multiplied by to get the $682.55 yearly cost.
- Is a electric tankless water heater expensive to run?
- Yes — at around $682.55 per year, a electric tankless water heater is one of the more costly appliances to run, so efficiency upgrades pay off quickly.
- How much CO₂ does a electric tankless water heater produce?
- On an average grid, a electric tankless water heater used this much is responsible for roughly 1606 kg of CO₂ per year. The exact figure depends on how clean your local electricity supply is.
- How can I reduce my electric tankless water heater running costs?
- Use it during off-peak hours if your utility offers time-of-use pricing, reduce daily run time, and consider an ENERGY STAR rated electric tankless water heater, which uses less power for the same job.