Mini tank water heater vs. electric water heater: running cost
A mini tank water heater is cheaper to run: about $81 a year versus $810 for an electric water heater at typical use and 17.99¢/kWh, a $729 difference.
| Mini tank water heater | Electric water heater | |
|---|---|---|
| Typical watts | 1,440 W | 4,500 W |
| Watt range | 1,000–2,000 W | 3,000–5,500 W |
| Typical use | 450 kWh a year | 4,500 kWh a year |
| Energy per year | 450 kWh | 4,500 kWh |
| Cost per hour | 0.9¢ | 9.2¢ |
| Cost per day | 22¢ | $2.22 |
| Cost per month | $6.75 | $67.46 |
| Cost per year | $81 | $810 |
| Per year in Hawaii (43.51¢) | $196 | $1,958 |
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What drives the difference
- Mini tank water heater: Mini tanks (2.5-7 gallons) plug into a 120 V outlet and draw about 1,440 W; standby heat loss of about 0.4-0.6 kWh a day is most of their annual use.
- Electric water heater: A 40-50 gallon electric tank serving 3-4 people typically uses 4,000-5,000 kWh a year, including 400-600 kWh of standby heat loss. Water heating is often the second-largest electric load in a home.
Ways to cut either cost
Avoids keeping water hot 24 hours a day.
See options on AmazonUses 60-70% less electricity, saving roughly 2,500-3,000 kWh a year.
See options on AmazonWe may earn a commission from qualifying purchases. It never changes the numbers we show. Disclosure.
Frequently asked questions
Which costs more to run, a mini tank water heater or an electric water heater?
At typical use and the U.S. average rate (17.99¢/kWh), an electric water heater costs about $810 a year versus $81 for a mini tank water heater. That's $729 more, or 10.0× as much.
How many watts do mini tank water heater and electric water heater use?
A mini tank water heater typically draws 1,440 W (range 1,000–2,000 W). An electric water heater draws 4,500 W (range 3,000–5,500 W). Watts alone don't decide cost. Hours of use, cycling and standby matter just as much.
Rates: EIA, 12 months ending 2026-07. Methodology.