How Much Does It Cost to Run a Grow Light?
A 600-watt-class grow light on a 12-hour cycle is one of the few hobby loads that rivals major appliances — the light bill is part of the grow budget. At the US-average rate of 16.5¢/kWh, running a grow light costs about $36.09/month ($433.09/year) at typical use. Adjust the watts, hours, and your rate below for your exact number.
Cost to run a grow light
$433/yr
- Per day
- $1.19
- Per month
- $36.09
- Energy per year
- 2,628 kWh
Cost = power (kW) × hours × days × your rate. Defaults are typical values — enter your appliance's actual watts (often on a label) and your real rate for a precise figure.
How much electricity does a grow light use?
At 600 W for 12 hours a day, a grow light uses about 7.2 kWh per day — roughly 219 kWh per month and 2,628 kWh per year. That's about 25% of the 863 kWh the average US home uses in a month. Energy use is the same everywhere — only the price per kWh changes your bill.
Wondering about the circuit instead? See how many amps a grow light draws.
Cost to run a grow light by electricity rate
Same 600 W appliance, 12 h/day — the bill changes with where you live.
| Scenario | Rate | Per month | Per year |
|---|---|---|---|
| Cheapest states (North Dakota) | 11.5¢ | $25.21 | $302.48 |
| US average | 16.5¢ | $36.09 | $433.09 |
| Most expensive (Hawaii) | 42.9¢ | $93.86 | $1,126.36 |
Find your state's rate on the electricity rates by state page, or see the appliance wattage chart for more devices.
Measure what a grow light really costs you
The estimate above uses typical wattage and hours. A plug-in energy meter logs the kilowatt-hours this appliance actually uses — leave it in for a week, multiply by your rate, and the estimate becomes a measurement. A whole-home monitor does the same for every circuit at once, but its sensors install inside the panel.
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Plug-in power meter
P3 International Kill A Watt P4400
Best for: Measuring what one plug-in appliance really uses
Whole-home energy monitor
Emporia Vue 3 Home Energy Monitor (16 circuit sensors)
Best for: Measuring hardwired and 240 V loads, or every circuit at once
Frequently asked questions
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