How Much Does It Cost to Run an LED Grow Light? $2/Month

36 W (15–48 W)Typical power draw

12 h/day, 30.4 days/monthAssumed use

0.43 kWhEnergy per day

Updated September 2026 · Source: EIA Electric Power Monthly Table 5.6.A (July 2026 data) · next EIA update ~Oct 23

On this page: Calculator Table How we calculated Sources

Power draw (watts) — typical for led grow light: 15–48 W; check your label Hours per day for an LED grow light — effective run-hours Days per month — 30 = every day Months used per year — 12 for led grow light; seasonal loads do not run all year Quick-fill your state's EIA average rate Your rate (¢/kWh) — 17¢ = EIA 2025 annual US average (July 2026 monthly: 18.31¢)

Energy used: — per day

Cost per hour: —

Cost per day: —

Cost per month in use: —

Cost per year: —

an LED grow light: energy cost only (36 W ÷ 1,000 × hours × rate); fixed fees and taxes extra.

What changes if… Electricity rates move Compare it with charging an EV at home

Slider nudges the rate for an LED grow light; the URL keeps it.

## How much does it cost to run an LED grow light?

The same an LED grow light at 12 hours a day costs $1.58 a month at 12¢ and $5.91 at 45¢ — usage held constant, only the rate moving:

Table 1: How Much Does It Cost to Run an LED Grow Light? $2/Month
Electricity rate	Per hour	Per day	Per month	Per year
12¢/kWh	$0.004	$0.05	$1.58	$19
15¢/kWh	$0.005	$0.06	$1.97	$24
17¢/kWh (US avg)	$0.006	$0.07	$2.23	$27
20¢/kWh	$0.007	$0.09	$2.63	$32
25¢/kWh	$0.009	$0.11	$3.28	$39
30¢/kWh	$0.011	$0.13	$3.94	$47
35¢/kWh	$0.013	$0.15	$4.60	$55
45¢/kWh	$0.016	$0.19	$5.91	$71

Typical power draw: 36 W (15–48 W)
Assumed use: 12 h/day, 30.4 days/month
Energy per day: 0.43 kWh
Cost per day: $0.07
Cost per month: $2.23
Cost per year: $27

Why this number

Running an LED grow light at 36 watts for 12 hours a day costs about $0.07 a day and $2.23 a month at 17¢/kWh, the EIA 2025 annual US average (July 2026 monthly: 18.31¢) — roughly $27 a year. The formula for an LED grow light: 36 W ÷ 1,000 × hours × your rate per kWh. For an LED grow light your own rate changes the answer: at 12¢/kWh that month costs $1.58, at 45¢/kWh it costs $5.91.

An LED grow light rated at 36 watts, run 12 hours a day, costs about $0.07 a day — about $2.23 a month, or $27 a year — at the US average electricity rate of 17¢/kWh. That places it 31th of the 40 appliances tracked here, near the bottom. It is not where a high bill comes from, and switching it off will not rescue one.

What actually drives this number

The assumption: a 36 W panel on a timer 12 hours a day, all year — the photoperiod Soltech publishes for its 36 W Aspect fixture and medium-light plants. AeroGarden’s own range brackets it: the 15 W Harvest runs 15 hours on its built-in timer (~82 kWh/yr) while the 48 W Bounty at 17 hours reaches ~298 kWh/yr (AeroGarden’s own electricity FAQ ). If you only start seedlings in spring, you are running roughly a third of the year — divide accordingly.

For an LED grow light the unit that matters is the kilowatt-hour, not the kilowatt : 36 W is only the rate of use, and 12 hours a day is what turns it into the 158 kWh a year you are actually billed for. On that yearly measure its nearest always-on neighbor is the Wi-Fi router and modem at about 131 kWh.

Where this number comes from

Benchmark: 158 kWh/year — Soltech’s published fixture specs — details in the note above
Assumed use for an LED grow light: 12 h/day, 30.4 days/month, 12 months/year — every one of these is editable in the calculator above
Rate for an LED grow light: 17¢/kWh, the EIA 2025 annual US average (July 2026 monthly: 18.31¢), from EIA Electric Power Monthly, Table 5.6.A ; the state selector above fills in yours

Putting LED grow light in proportion

At 17¢/kWh, an LED grow light next to the rest of the bill:

LED grow light at $2.23 a month is close to Hair dryer at $1.91, and just under 65-inch LED TV at $2.55
One hour of an LED grow light uses as much as roughly an hour of a typical always-on device
Over a year an LED grow light comes to $27 — about 0.2 months of a $150 monthly electricity bill

For an LED grow light: this is an always-on load, and that is the whole story. LED grow light’s wattage is unremarkable; the 24-hour duty cycle is what puts an LED grow light where it is. Reducing run-hours is usually impossible for an LED grow light, which makes efficiency at purchase time the only real decision. On this site’s own numbers, an LED grow light lands at #31 of 40 on the monthly-cost ranking, at about $2.23 for a typical month.

The formula, in full

The 36 W arithmetic for an LED grow light, step by step:

Watts to kilowatts. 36 W ÷ 1,000 = 0.04 kW.
Energy per day. 0.04 kW × 12 hours = 0.43 kWh.
Cost per day. 0.43 kWh × $0.17 = $0.07.
Cost per month. $0.07 × 30.4 days = $2.23.

For an LED grow light the two levers are run-hours (12 h/day here) and your rate; at 12 hours a day, 36 W adds up — which is why always-on loads dominate the rankings.

Other always-on loads: Wi-Fi router and modem ($22/yr), Washing machine ($11/yr), Water softener ($4/yr). Closest on annual cost: Hair dryer ($23/yr), 65-inch LED TV ($31/yr). Across all other always-on loads here, the priciest is Pool pump at $40.80/mo.

The an LED grow light table above runs a fixed rate ladder (12–45¢); the state quick-fill uses July 2026 averages from EIA Electric Power Monthly, Table 5.6.A .

Put an LED grow light ($2.23 a month) against everything else in the electricity cost calculator , check your state’s rate , or browse all 40 appliances ; year-round high bills: solar savings calculator .

Frequently asked questions

How much does it cost to run an LED grow light per hour?

About $0.006 an hour for an LED grow light at 17¢/kWh, the EIA 2025 annual US average (July 2026 monthly: 18.31¢), for a 36 W unit. The calculation is 36 ÷ 1,000 × 1 hour × $0.17 per kWh. At 30¢/kWh the same hour costs $0.011.

How much does an LED grow light add to my monthly bill?

Roughly $2.23 a month for an LED grow light at 12 hours a day, 30.4 days a month, 17¢/kWh. That is about $27 a year if you use it that much year-round. For an LED grow light, change the 12-hour default to your own use — run-time moves the total as much as the 36 W does.

How many watts does an LED grow light use?

Typically around 36 W, with real units ranging from about 15 to 48 W depending on size, model and setting. The nameplate on your own unit is the figure to trust — these are typical values for planning, not a measurement of your appliance.

Why is my actual bill higher than the an LED grow light figure?

$2.23 a month is the energy cost of an LED grow light alone; your bill adds fixed connection charges, delivery fees, taxes and every other load. Add the other appliances in the index to an LED grow light for the controllable part of the bill.

How we calculated this

Worked for an LED grow light: 36 W ÷ 1,000 × 12 h × $0.17 = $0.07 a day; × 30.4 days = $2.23 a month; × 12 months in use = $27 a year. 36 W and 12 h are the typical figures cited for an LED grow light; 17¢ is EIA’s 2025 annual US average.

Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.

Where to go next

Cost to run hair dryer — The next cheaper item on the list: $1.91 a month against an LED grow light’s $2.23.
Cost to run 65-inch led tv — The next pricier item: $2.55 a month, which puts an LED grow light in proportion.
All 40 appliances ranked by monthly cost — LED grow light is 31 of 40; the full ranking at 17¢/kWh.
Electricity cost calculator — Any wattage and hours, not just an LED grow light — with the state quick-fill.
Find your electricity rate by ZIP — Your own utility’s average rate, sent straight into the an LED grow light calculator.