💧 Water, Pool & Spa
How Much Does a Tankless Electric Water Heater Cost to Run?
At the current U.S. average rate of 18.8¢/kWh (April 2026), a tankless electric water heater costs about $72.01 per month at typical usage — 0.7 hours/day.
Per hour
$3.38
at 13,000–27,000 W
Per day
$2.37
0.7 hours/day
Per month
$72.01
383 kWh
Per year
$865
4,599 kWh
Whole-house electric tankless units draw a startling 13–27 kW while a tap runs — often the largest instantaneous load in the house — but only run during actual hot-water use. Total monthly energy usually lands modestly below an equivalent tank by eliminating standby losses.
Calculate it for your home
Per hour
$3.38
Per day
$2.37
Per month
$72.01
Per year
$865
Uses 383 kWh/month at 18.8¢ per kWh.
Cheapest and most expensive states
Monthly cost at typical usage, using each state's current average residential rate.
Cost in every state
| State | Rate (¢/kWh) | Per hour | Per month | Per year |
|---|---|---|---|---|
| North Dakota | 12.4 | $2.23 | $47.50 | $570 |
| Idaho | 12.7 | $2.29 | $48.65 | $584 |
| Nebraska | 13.3 | $2.39 | $50.94 | $612 |
| Oklahoma | 13.3 | $2.39 | $50.94 | $612 |
| Utah | 13.3 | $2.39 | $50.94 | $612 |
| Iowa | 13.9 | $2.50 | $53.24 | $639 |
| Montana | 13.9 | $2.50 | $53.24 | $639 |
| Missouri | 14.0 | $2.52 | $53.63 | $644 |
| Arkansas | 14.2 | $2.56 | $54.39 | $653 |
| Nevada | 14.3 | $2.57 | $54.77 | $658 |
| Louisiana | 14.4 | $2.59 | $55.16 | $662 |
| Washington | 14.4 | $2.59 | $55.16 | $662 |
| South Dakota | 14.5 | $2.61 | $55.54 | $667 |
| Wyoming | 14.7 | $2.65 | $56.31 | $676 |
| Tennessee | 14.9 | $2.68 | $57.07 | $685 |
| Kentucky | 15.0 | $2.70 | $57.46 | $690 |
| New Mexico | 15.2 | $2.74 | $58.22 | $699 |
| Florida | 15.4 | $2.77 | $58.99 | $708 |
| Georgia | 15.4 | $2.77 | $58.99 | $708 |
| Arizona | 15.5 | $2.79 | $59.37 | $713 |
| Kansas | 15.8 | $2.84 | $60.52 | $727 |
| Oregon | 15.8 | $2.84 | $60.52 | $727 |
| West Virginia | 16.1 | $2.90 | $61.67 | $740 |
| North Carolina | 16.3 | $2.93 | $62.44 | $750 |
| Minnesota | 16.4 | $2.95 | $62.82 | $754 |
| Colorado | 16.5 | $2.97 | $63.20 | $759 |
| Mississippi | 16.8 | $3.02 | $64.35 | $773 |
| Texas | 17.0 | $3.06 | $65.12 | $782 |
| South Carolina | 17.1 | $3.08 | $65.50 | $786 |
| Alabama | 17.4 | $3.13 | $66.65 | $800 |
| Virginia | 17.4 | $3.13 | $66.65 | $800 |
| Indiana | 17.9 | $3.22 | $68.56 | $823 |
| Delaware | 18.8 | $3.38 | $72.01 | $865 |
| Wisconsin | 19.2 | $3.46 | $73.54 | $883 |
| Ohio | 19.5 | $3.51 | $74.69 | $897 |
| Illinois | 20.5 | $3.69 | $78.52 | $943 |
| Michigan | 21.4 | $3.85 | $81.97 | $984 |
| Pennsylvania | 21.5 | $3.87 | $82.35 | $989 |
| Maryland | 22.1 | $3.98 | $84.65 | $1,016 |
| New Jersey | 23.5 | $4.23 | $90.01 | $1,081 |
| Vermont | 24.6 | $4.43 | $94.23 | $1,131 |
| Washington, D.C. | 25.4 | $4.57 | $97.29 | $1,168 |
| New Hampshire | 27.2 | $4.90 | $104 | $1,251 |
| Alaska | 27.4 | $4.93 | $105 | $1,260 |
| Rhode Island | 28.3 | $5.09 | $108 | $1,302 |
| Maine | 28.4 | $5.11 | $109 | $1,306 |
| Massachusetts | 29.5 | $5.31 | $113 | $1,357 |
| New York | 29.5 | $5.31 | $113 | $1,357 |
| Connecticut | 32.2 | $5.80 | $123 | $1,481 |
| California | 35.3 | $6.35 | $135 | $1,623 |
| Hawaii | 46.6 | $8.39 | $178 | $2,143 |
How to lower the cost
- Set water heaters to 120°F and fix dripping hot taps quickly — a drip is a slow leak of paid heat.
- Shorter showers and low-flow heads cut costs directly; hot water is usually a top-three energy use.
- Timers and covers transform pool, spa, and tank costs — stored heat and off-hours running are much cheaper.
Frequently asked questions
How much electricity does a tankless electric water heater use?
A typical tankless electric water heater draws about 18,000 watts in use. At 0.7 hours/day, that works out to roughly 13 kWh per day, or 383 kWh per month.
How much does it cost to run a tankless electric water heater for 1 hour?
At the current U.S. average residential rate of 18.8¢/kWh, one hour costs about $3.38. In North Dakota (12.4¢/kWh) it's $2.23, while in Hawaii (46.6¢/kWh) it's $8.39.
How much does a tankless electric water heater cost to run per month?
With typical usage (0.7 hours/day), expect about $72.01 per month at the U.S. average rate — from $47.50 in North Dakota up to $178 in Hawaii. Rates are as of April 2026.
Does a tankless electric water heater use a lot of electricity?
Yes — at typical usage it accounts for roughly 43% of an average U.S. home's monthly consumption (885 kWh), which makes it one of the larger loads in the house.