lighting · 100W typical

Running a indoor grow light (led) costs about $5.94/month.

That's the typical indoor grow light (led) at 100W, run 12 hours a day at the US-average rate of 16.5¢/kWh. Change any of those and the number moves — use the calculator below to see yours.

Estimated cost

$5.94/month

$0.20 per day$72.27 per year36.0 kWh monthly

Wattage

Hours / day

Your rate

Full-power draw for 12 hours at 16.5¢/kWh.

How you use it

Cost shifts with how long it's on.

The same indoor grow light (led) can cost very different amounts depending on usage patterns. Three common scenarios, at the US-average rate.

flowering cycle

$5.94

per month

12/12 flower cycle

12 hrs/day·$72.27/yr

vegetative

$8.91

per month

18/6 veg cycle

18 hrs/day·$108.41/yr

seedling starts

$7.92

per month

spring seedling station

16 hrs/day·$96.36/yr

Where you live

$10.76 spread between the cheapest and priciest states.

Same appliance, same hours of use, different zip code — the monthly cost varies this much.

State	Rate	Monthly	Yearly
Hawaii	41.2¢	$14.83	$180.46
California	31.4¢	$11.30	$137.53
Massachusetts	30.8¢	$11.09	$134.90
Connecticut	28.7¢	$10.33	$125.71
Rhode Island	27.9¢	$10.04	$122.20
New Hampshire	24.6¢	$8.86	$107.75
Alaska	24.3¢	$8.75	$106.43
New York	22.3¢	$8.03	$97.67
Maine	22.1¢	$7.96	$96.80
Vermont	21.5¢	$7.74	$94.17
Michigan	19.3¢	$6.95	$84.53
New Jersey	19.1¢	$6.88	$83.66
Maryland	18.4¢	$6.62	$80.59
Pennsylvania	18.1¢	$6.52	$79.28
District of Columbia	17.8¢	$6.41	$77.96
Wisconsin	17.4¢	$6.26	$76.21
Delaware	17.2¢	$6.19	$75.34
Illinois	16.9¢	$6.08	$74.02
Ohio	16.6¢	$5.98	$72.71
Nevada	16.3¢	$5.87	$71.39
Indiana	15.8¢	$5.69	$69.20
Virginia	15.7¢	$5.65	$68.77
Minnesota	15.6¢	$5.62	$68.33
Colorado	15.4¢	$5.54	$67.45
Alabama	15.2¢	$5.47	$66.58
West Virginia	15.2¢	$5.47	$66.58
Florida	15.1¢	$5.44	$66.14
New Mexico	14.8¢	$5.33	$64.82
Texas	14.8¢	$5.33	$64.82
Arizona	14.7¢	$5.29	$64.39
South Carolina	14.7¢	$5.29	$64.39
Kansas	14.6¢	$5.26	$63.95
Georgia	14.2¢	$5.11	$62.20
Iowa	14.1¢	$5.08	$61.76
North Carolina	13.9¢	$5.00	$60.88
Missouri	13.6¢	$4.90	$59.57
Oregon	13.4¢	$4.82	$58.69
Tennessee	13.3¢	$4.79	$58.25
Kentucky	13.2¢	$4.75	$57.82
Mississippi	13.1¢	$4.72	$57.38
Oklahoma	13.1¢	$4.72	$57.38
South Dakota	12.7¢	$4.57	$55.63
Montana	12.4¢	$4.46	$54.31
Nebraska	12.2¢	$4.39	$53.44
Arkansas	12.1¢	$4.36	$53.00
Washington	12.1¢	$4.36	$53.00
Louisiana	11.9¢	$4.28	$52.12
Wyoming	11.6¢	$4.18	$50.81
North Dakota	11.5¢	$4.14	$50.37
Utah	11.4¢	$4.10	$49.93
Idaho	11.3¢	$4.07	$49.49

Efficient vs. inefficient

A $701.02/year difference across the wattage range.

Swapping a high-draw model for an efficient one pays for itself. Here's what that looks like annually at typical usage.

Most efficient

30W

$1.78 per month

$21.68 per year

Typical

100W

$5.94 per month

$72.27 per year

High draw

1000W

$59.40 per month

$722.70 per year

When it hits hardest

winter peak

Heavier winter and early spring for indoor growing.

Ways to cut the cost

1
Use LED instead of HPS/MH — 40-50% less watts per PAR output
Saves 300-500 kWh/month at typical cycle
2
Dial in exact photoperiod — over-running wastes kWh
Exact timing cuts 10-20% runtime
3
Use a light meter to avoid over-lighting
Plants don't use the extra light — pure waste

Real-world wattages

Pulled from actual spec sheets.

Brand	Model	Watts
Spider Farmer	SF-1000	100W
Mars Hydro	TS 600	70W
GE	Balanced Spectrum Grow LED	32W

Picks that actually move the needle

Three products worth comparing if you're thinking about upgrading or supplementing what you have.

Some links below are affiliate links. If you buy, we may earn a small commission — it never changes the price you pay, and we only recommend picks we would stand behind.

Spider Farmer SF-1000 LED Grow Light

Samsung diodes — 2.75 μmol/J efficiency

$130-180

Mars Hydro TS 600 LED Grow Light

70W budget full-spectrum

$70-100

Smart Plug Timer for Grow Lights

Programmable for exact photoperiod

$18-25