💧 Water, Pool & Spa
How Much Does a Tankless Electric Water Heater Cost to Run?
At the current U.S. average rate of 18.3¢/kWh (July 2026), a tankless electric water heater costs about $70.10 per month at typical usage — 0.7 hours/day.
Per hour
$3.29
at 13,000–27,000 W
Per day
$2.31
0.7 hours/day
Per month
$70.10
383 kWh
Per year
$842
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
$3.29
Per day
$2.31
Per month
$70.10
Per year
$842
Uses 383 kWh/month at 18.3¢ 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 |
|---|---|---|---|---|
| Louisiana | 12.7 | $2.29 | $48.65 | $584 |
| Nevada | 12.8 | $2.30 | $49.03 | $589 |
| Utah | 13.1 | $2.36 | $50.18 | $602 |
| North Dakota | 13.4 | $2.41 | $51.33 | $616 |
| Idaho | 13.7 | $2.47 | $52.48 | $630 |
| Tennessee | 13.7 | $2.47 | $52.48 | $630 |
| Kentucky | 13.8 | $2.48 | $52.86 | $635 |
| Nebraska | 13.8 | $2.48 | $52.86 | $635 |
| Arkansas | 14.3 | $2.57 | $54.77 | $658 |
| Oklahoma | 14.4 | $2.59 | $55.16 | $662 |
| Wyoming | 14.4 | $2.59 | $55.16 | $662 |
| Mississippi | 14.5 | $2.61 | $55.54 | $667 |
| Washington | 14.7 | $2.65 | $56.31 | $676 |
| Florida | 15.0 | $2.70 | $57.46 | $690 |
| Montana | 15.0 | $2.70 | $57.46 | $690 |
| North Carolina | 15.2 | $2.74 | $58.22 | $699 |
| Kansas | 15.3 | $2.75 | $58.61 | $704 |
| Arizona | 15.4 | $2.77 | $58.99 | $708 |
| South Dakota | 15.4 | $2.77 | $58.99 | $708 |
| South Carolina | 15.5 | $2.79 | $59.37 | $713 |
| West Virginia | 15.8 | $2.84 | $60.52 | $727 |
| Texas | 15.9 | $2.86 | $60.90 | $731 |
| Iowa | 16.0 | $2.88 | $61.29 | $736 |
| Oregon | 16.0 | $2.88 | $61.29 | $736 |
| Missouri | 16.1 | $2.90 | $61.67 | $740 |
| New Mexico | 16.1 | $2.90 | $61.67 | $740 |
| Georgia | 16.3 | $2.93 | $62.44 | $750 |
| Alabama | 16.4 | $2.95 | $62.82 | $754 |
| Indiana | 16.7 | $3.01 | $63.97 | $768 |
| Colorado | 17.0 | $3.06 | $65.12 | $782 |
| Minnesota | 17.5 | $3.15 | $67.03 | $805 |
| Virginia | 17.6 | $3.17 | $67.42 | $809 |
| Delaware | 18.5 | $3.33 | $70.86 | $851 |
| Wisconsin | 19.1 | $3.44 | $73.16 | $878 |
| Illinois | 19.2 | $3.46 | $73.54 | $883 |
| Ohio | 19.5 | $3.51 | $74.69 | $897 |
| Maryland | 21.4 | $3.85 | $81.97 | $984 |
| Pennsylvania | 21.7 | $3.91 | $83.12 | $998 |
| Michigan | 23.1 | $4.16 | $88.48 | $1,062 |
| Vermont | 23.8 | $4.28 | $91.16 | $1,095 |
| Connecticut | 24.2 | $4.36 | $92.70 | $1,113 |
| Washington, D.C. | 25.2 | $4.54 | $96.53 | $1,159 |
| New Jersey | 25.2 | $4.54 | $96.53 | $1,159 |
| New Hampshire | 26.6 | $4.79 | $102 | $1,223 |
| Rhode Island | 28.3 | $5.09 | $108 | $1,302 |
| Alaska | 28.8 | $5.18 | $110 | $1,325 |
| New York | 29.9 | $5.38 | $115 | $1,375 |
| Massachusetts | 30.5 | $5.49 | $117 | $1,403 |
| Maine | 32.4 | $5.83 | $124 | $1,490 |
| California | 33.6 | $6.05 | $129 | $1,545 |
| Hawaii | 48.0 | $8.64 | $184 | $2,208 |
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 18.3¢/kWh, one hour costs about $3.29. In Louisiana (12.7¢/kWh) it's $2.29, while in Hawaii (48¢/kWh) it's $8.64.
How much does a tankless electric water heater cost to run per month?
With typical usage (0.7 hours/day), expect about $70.10 per month at the U.S. average rate — from $48.65 in Louisiana up to $184 in Hawaii. Rates are as of July 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.