How much does it cost to run a grow light?
A grow light costs about 3.6¢ per hour, 58¢ a day, $17.52 a month and $210 a year at typical use (16 hours a day) and the U.S. average rate of 17.99¢/kWh. Full-spectrum LED grow lights draw roughly 30-40 W per square foot of flowering canopy; seedlings and vegetative growth run 16-18 hours a day, flowering 12.
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Cost by setting
| Setting | Watts | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|---|
| Houseplant / seedling light | 30 | 0.5¢ | 8.6¢ | $2.63 | $32 |
| 2x2 tent LED | 100 | 1.8¢ | 29¢ | $8.76 | $105 |
| 2x4 / 3x3 tent LED | 200 | 3.6¢ | 58¢ | $17.52 | $210 |
| 4x4 tent LED | 450 | 8.1¢ | $1.30 | $39.43 | $473 |
| 1000 W HPS | 1,100 | 20¢ | $3.17 | $96.37 | $1,156 |
At 16 hours a day and 17.99¢/kWh.
Cost by hours of use
| Hours per day | kWh/day | Per day | Per month | Per year (all year) |
|---|---|---|---|---|
| 1 hour | 0.20 | 3.6¢ | $1.10 | $13 |
| 2 hours | 0.40 | 7.2¢ | $2.19 | $26 |
| 4 hours | 0.80 | 14¢ | $4.38 | $53 |
| 8 hours | 1.60 | 29¢ | $8.76 | $105 |
| 12 hours | 2.40 | 43¢ | $13.14 | $158 |
| 24 hours | 4.80 | 86¢ | $26.28 | $315 |
Cost to run a grow light in every state
The same grow light costs $144 a year in North Dakota and $509 in Hawaii, at each state's average residential rate (12 months ending July 2026).
| State | Rate | Per hour | Per month | Per year |
|---|---|---|---|---|
| North Dakota | 12.32¢ | 2.5¢ | $12.00 | $144 |
| Idaho | 12.65¢ | 2.5¢ | $12.32 | $148 |
| Nebraska | 12.86¢ | 2.6¢ | $12.53 | $150 |
| Louisiana | 12.99¢ | 2.6¢ | $12.65 | $152 |
| Utah | 13.32¢ | 2.7¢ | $12.97 | $156 |
| Nevada | 13.36¢ | 2.7¢ | $13.01 | $156 |
| Arkansas | 13.43¢ | 2.7¢ | $13.08 | $157 |
| Tennessee | 13.56¢ | 2.7¢ | $13.21 | $158 |
| Oklahoma | 13.70¢ | 2.7¢ | $13.34 | $160 |
| Montana | 13.84¢ | 2.8¢ | $13.48 | $162 |
| Kentucky | 13.92¢ | 2.8¢ | $13.56 | $163 |
| Missouri | 13.95¢ | 2.8¢ | $13.59 | $163 |
| Wyoming | 14.01¢ | 2.8¢ | $13.65 | $164 |
| Washington | 14.12¢ | 2.8¢ | $13.75 | $165 |
| Iowa | 14.13¢ | 2.8¢ | $13.76 | $165 |
| South Dakota | 14.20¢ | 2.8¢ | $13.83 | $166 |
| Mississippi | 14.77¢ | 3.0¢ | $14.39 | $173 |
| North Carolina | 14.77¢ | 3.0¢ | $14.39 | $173 |
| Kansas | 15.09¢ | 3.0¢ | $14.70 | $176 |
| Georgia | 15.12¢ | 3.0¢ | $14.73 | $177 |
| New Mexico | 15.32¢ | 3.1¢ | $14.92 | $179 |
| Florida | 15.39¢ | 3.1¢ | $14.99 | $180 |
| Arizona | 15.40¢ | 3.1¢ | $15.00 | $180 |
| West Virginia | 15.48¢ | 3.1¢ | $15.08 | $181 |
| Oregon | 15.50¢ | 3.1¢ | $15.10 | $181 |
| South Carolina | 15.64¢ | 3.1¢ | $15.23 | $183 |
| Texas | 15.96¢ | 3.2¢ | $15.55 | $187 |
| Minnesota | 16.22¢ | 3.2¢ | $15.80 | $190 |
| Alabama | 16.44¢ | 3.3¢ | $16.01 | $192 |
| Virginia | 16.48¢ | 3.3¢ | $16.05 | $193 |
| Colorado | 16.58¢ | 3.3¢ | $16.15 | $194 |
| Indiana | 16.94¢ | 3.4¢ | $16.50 | $198 |
| Delaware | 17.79¢ | 3.6¢ | $17.33 | $208 |
| Ohio | 18.25¢ | 3.6¢ | $17.78 | $213 |
| Wisconsin | 18.74¢ | 3.7¢ | $18.25 | $219 |
| Illinois | 18.79¢ | 3.8¢ | $18.30 | $220 |
| Pennsylvania | 20.70¢ | 4.1¢ | $20.16 | $242 |
| Maryland | 21.03¢ | 4.2¢ | $20.48 | $246 |
| Michigan | 21.05¢ | 4.2¢ | $20.50 | $246 |
| New Jersey | 23.78¢ | 4.8¢ | $23.16 | $278 |
| Vermont | 23.80¢ | 4.8¢ | $23.18 | $278 |
| District of Columbia | 24.20¢ | 4.8¢ | $23.57 | $283 |
| New Hampshire | 26.67¢ | 5.3¢ | $25.98 | $312 |
| Alaska | 26.85¢ | 5.4¢ | $26.15 | $314 |
| Connecticut | 27.99¢ | 5.6¢ | $27.26 | $327 |
| New York | 28.39¢ | 5.7¢ | $27.65 | $332 |
| Rhode Island | 29.27¢ | 5.9¢ | $28.51 | $342 |
| Maine | 29.31¢ | 5.9¢ | $28.55 | $343 |
| Massachusetts | 30.43¢ | 6.1¢ | $29.64 | $356 |
| California | 32.99¢ | 6.6¢ | $32.13 | $386 |
| Hawaii | 43.51¢ | 8.7¢ | $42.38 | $509 |
How to cut the cost
- Use 12-14 hours for leafy greens and herbs; 16-18 hours is only needed for some crops.
- Dim to 50-75% for seedlings and early veg.
- Choose fixtures rated 2.5+ µmol/J; they produce the same light with 30-40% less power than older LEDs or HPS.
- Use reflective tent walls so less light is wasted.
Cheaper ways to get the job done
Modern quantum-board LEDs deliver more usable light per watt than blurple panels or HPS.
See options on AmazonKeeps exact photoperiods so lights don't run extra hours.
See options on AmazonWe may earn a commission from qualifying purchases. It never changes the numbers we show. Disclosure.
Compare with similar appliances
| Appliance | Watts | Typical use | Per month | Per year |
|---|---|---|---|---|
| Grow light | 200 | 16 hours a day | $17.52 | $210 |
| LED bulb | 9 | 3 hours a day | $0.15 | $2 |
| LED shop light | 40 | 3 hours a day | $0.66 | $8 |
| Fluorescent tube light | 64 | 4 hours a day | $1.40 | $17 |
| Halogen floodlight | 90 | 3 hours a day | $1.48 | $18 |
| Incandescent bulb | 60 | 3 hours a day | $0.99 | $12 |
| Landscape lighting | 50 | 6 hours a day | $1.64 | $20 |
Head-to-head comparisons
Frequently asked questions
How much does it cost to run a grow light per hour?
A grow light drawing 200 watts uses 0.20 kWh per hour. At the U.S. average of 17.99¢/kWh that's 3.6¢ per hour. In North Dakota (12.32¢) it's 2.5¢. In Hawaii (43.51¢) it's 8.7¢.
How much does it cost to run a grow light per month?
At typical use (16 hours a day), a grow light costs about $17.52 a month and $210 a year, at the U.S. average rate. Enter your ZIP in the calculator above for your utility's rate.
How many watts does a grow light use?
Most grow lights use 15 to 1,100 watts, depending on the setting (houseplant / seedling light 30 W, 2x2 tent led 100 W, 2x4 / 3x3 tent led 200 W, 4x4 tent led 450 W, 1000 w hps 1,100 W). Check the label on the back or bottom for your model's exact rating.
How many kWh does a grow light use?
About 3.20 kWh a day and 1,169 kWh a year at typical use (16 hours a day).
Does a grow light use a lot of electricity?
It's a moderate load: 1,169 kWh a year is about 11% of the average U.S. home's yearly use.
Is it cheaper to run a grow light or an LED bulb?
At typical use, a grow light costs about $210 a year versus $2 for an LED bulb. So the LED bulb is cheaper by about $208 a year. Use the comparison table above to compare them at your own settings.
How can I lower the cost of running a grow light?
- Use 12-14 hours for leafy greens and herbs; 16-18 hours is only needed for some crops.
- Dim to 50-75% for seedlings and early veg.
- Choose fixtures rated 2.5+ µmol/J; they produce the same light with 30-40% less power than older LEDs or HPS.
Rates updated 2026-10-21: EIA data through July 2026. Typical wattage and usage reviewed against DOE, ENERGY STAR and manufacturer specs. Methodology.