At the US average rate for homes in 2025, 17.3¢ per kWh, an old 60 watt bulb left on for 24 hours costs about 25¢ a day, or $90.93 a year. Feit’s OM60DM/927CA, an LED 60 watt replacement that uses 8.8 watts, costs about 3.7¢ a day.
Cost of
W
W
W
h
¢/kWh
The rate starts at the US average for homes in 2025, and the hours at 24, a whole day. For several bulbs, type a sum, such as 60 + 60 + 40.
Cost to run
25¢ a day
60 W × 24 h = 1.44 kWh a day. 1.44 kWh × 17.3¢ = 25¢ a day. $7.47 a month (30 days), $90.93 a year (365 days).
Use the watts under Energy Used on a bulb’s Lighting Facts label, or the watts on a device’s nameplate. The cost assumes it draws those watts the whole time it’s on.
For your own rate, divide the electricity charges on your bill by the kWh it lists, then multiply by 100 for cents.
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Old bulb vs LED, by hours left on
What a light costs to leave on at 17.3 cents per kWh
Left on
Old 60 W bulb
8.8 W LED
1 hour
1¢
0.2¢
8 hours
8.3¢
1.2¢
12 hours
12¢
1.8¢
24 hours
25¢
3.7¢
24 hours a day for a year
$90.93
$13.34
Rounded to the cent or tenth of a cent.
Your own bulb
An LED’s box gives two watt figures: the equivalent watts, for the old bulb it replaces, and the watts it really uses, under Energy Used on the Lighting Facts label. The cost comes from the second one.
Your own rate
Left on all day at North Dakota’s average for homes, 12.36¢ per kWh from January to July 2026 and the lowest of any state, the old 60 watt bulb costs 18¢ a day. At Hawaii’s 46.28¢, the highest, it costs 67¢.
Common questions
What does a 100 watt bulb cost to leave on all day?
At 17.3 cents per kWh, 100 watts for 24 hours is 2.4 kWh: about 42 cents a day, or $151.55 a year. To replace it with an LED of the same brightness, choose one with at least 1,600 lumens.
Why is it so much more than the yearly cost on the box?
The box's yearly cost assumes the bulb is on for 3 hours a day at 11 cents per kWh. Left on all day at 17.3 cents, the same bulb costs about 12.6 times as much.
The default rate is the US Energy Information Administration’s average residential price, the LED’s watts come from Feit’s product page, the brightness from ENERGY STAR (EPA), and the label details from the FTC’s labeling rule. Checked against published data from FTC, ENERGY STAR, US EIA and Feit Electric.
ENERGY STAR (EPA), “Learn About Brightness”: lumens, not watts, and the watts-to-lumens table
US Energy Information Administration, Electric Power Monthly (released September 24, 2026), Table 5.3: average price of electricity to ultimate customers, 2025 annual residential, and Table 5.6.B: by state, year to date through July 2026
Feit Electric product page: 8.8W (60W Replacement) Soft White (2700K) A19 E26 Base Dimmable LED (OM60DM/927CA/4)
General guidance from manufacturer and standards data. Products vary, so check the label and the maker's instructions.