Running a light typically costs less than 1 cent to about 10 cents per hour, depending mainly on bulb wattage, electricity rates, and how many bulbs are on. An LED usually costs a fraction of a cent to around 2 cents per hour, while older incandescent bulbs can cost several cents per hour for the same light output.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| LED bulb, per hour | $0.001 | $0.01 | $0.02 | Uses about 8-15 watts; assumes electricity at $0.15-$0.20 per kWh |
| CFL bulb, per hour | $0.002 | $0.01 | $0.03 | Often uses 13-23 watts |
| Incandescent bulb, per hour | $0.008 | $0.09 | $0.15 | Assumes 60-100 watts and higher electricity rates |
| Typical household lighting, per hour | $0.03 | $0.10 | $0.35 | Several bulbs operating together |
Assumptions: U.S. residential electricity prices vary by utility and location; example rates in this article range from $0.12 to $0.30 per kilowatt-hour.
What running one light costs per hour
A single LED bulb generally costs about $0.001-$0.02 per hour to run. At a common electricity rate of $0.16 per kWh, a 10-watt LED costs about $0.0016 per hour, or roughly 0.16 cents. A 60-watt incandescent bulb at the same rate costs about $0.0096 per hour.
For most homes, the bulb’s wattage and the local price per kWh matter more than the number of hours in a single day. A lamp with two 10-watt LEDs costs about twice as much to operate as one such bulb, while a 100-watt fixture uses five times the electricity of a 20-watt fixture.
The basic estimate is watts ÷ 1,000 × electricity rate per kWh. For example, a 12-watt bulb at $0.18 per kWh costs 0.012 × $0.18, or about $0.0022 per hour. That is less than a quarter of a cent. The figure covers energy use, not the bulb’s purchase price or any separate service fees on a utility bill.
How watts and electricity rates shape the hourly bill
Wattage measures how much electricity a bulb uses while switched on. The kWh is the billing unit: using 1,000 watts for one hour equals 1 kWh. A bulb rated at 10 watts running for 100 hours also uses 1 kWh. The bill’s energy charge is found by multiplying those kWh by the rate charged by the utility.
| Bulb or fixture load | Energy per hour | At $0.12/kWh | At $0.20/kWh | At $0.30/kWh |
|---|---|---|---|---|
| 8-watt LED | 0.008 kWh | $0.001 | $0.002 | $0.002 |
| 15-watt LED | 0.015 kWh | $0.002 | $0.003 | $0.005 |
| 60-watt incandescent | 0.060 kWh | $0.007 | $0.012 | $0.018 |
| 100-watt incandescent | 0.100 kWh | $0.012 | $0.020 | $0.030 |
A higher electric rate raises the cost in direct proportion: at $0.30 per kWh, the same bulb costs 2.5 times as much as at $0.12. Utility bills may also include fixed monthly charges, taxes, or delivery fees. Those expenses do not usually change with one extra hour of lighting, so the table estimates the variable energy charge rather than the full bill.
LED, CFL, halogen, and incandescent hourly prices
Bulbs that provide similar brightness can use very different amounts of power. An 800-lumen LED commonly uses about 8-12 watts, while a comparable incandescent bulb uses around 60 watts. The actual wattage is printed on the bulb or packaging; lumens indicate brightness and are more useful than wattage for comparing light output.
| Bulb type and example wattage | Cost per hour at $0.16/kWh | Typical cost range per hour | Price context |
|---|---|---|---|
| LED, 8-12 watts | $0.001-$0.002 | $0.001-$0.004 | Efficient choice for routine use |
| CFL, 13-23 watts | $0.002-$0.004 | $0.002-$0.007 | Uses less power than incandescent |
| Halogen, 40-70 watts | $0.006-$0.011 | $0.005-$0.021 | Often less efficient than LED or CFL |
| Incandescent, 60-100 watts | $0.010-$0.016 | $0.007-$0.030 | Higher use for similar brightness |
For equal brightness, replacing a 60-watt incandescent with a 10-watt LED cuts the bulb’s energy use by about 83%. Bulb life and purchase price affect the longer-term comparison, but they do not change the hourly electricity calculation. Specialty bulbs, such as high-output grow lights, may use hundreds of watts and fall outside these ordinary household ranges.
Which wattage and kWh rate change the estimate most?
Two practical thresholds help explain why estimates vary. First, every additional 10 watts adds 0.01 kWh for each hour of use. At $0.20 per kWh, that extra load adds $0.002 per hour, or 0.2 cents. Second, increasing the electricity rate from $0.15 to $0.30 per kWh doubles the energy charge without changing the bulb.
Check both the bulb’s actual watts and the energy rate on the utility bill before relying on a general average. A “60-watt equivalent” LED does not draw 60 watts; it may use only 8-10 watts. For a fixture with multiple sockets, add the wattage of all bulbs that are on at once. A 5-bulb chandelier with 8-watt LEDs draws 40 watts total, not 8 watts.
Dimmers can lower energy use when they reduce the light output, but the savings depend on the dimmer, bulb, and dimming level. A compatible LED set to half brightness may use less power than at full output, though it may not use exactly half. Smart bulbs and controls also draw a small amount of standby power; check manufacturer specifications if many devices stay connected around the clock.
What a lamp or multi-bulb fixture costs to operate
Room-level estimates depend on how many bulbs are on together. At $0.20 per kWh, one 10-watt LED costs $0.002 per hour. A four-bulb fixture using 10-watt LEDs draws 40 watts and costs about $0.008 per hour. A six-bulb fixture with 60-watt incandescent bulbs draws 360 watts and costs about $0.072 per hour.
| Lighting setup | Total watts | Cost per hour at $0.20/kWh | Cost for 5 hours |
|---|---|---|---|
| One 10-watt LED lamp | 10 watts | $0.002 | $0.01 |
| Four 10-watt LED bulbs | 40 watts | $0.008 | $0.04 |
| Six 60-watt incandescent bulbs | 360 watts | $0.072 | $0.36 |
| One 150-watt halogen floodlight | 150 watts | $0.030 | $0.15 |
Count the watts for the entire fixture, not just one socket, when estimating its hourly price. Some integrated LED ceiling fixtures list total fixture wattage rather than a replaceable bulb rating. Landscape and security lights can also have multiple lamps or operate for long periods, making their combined use more significant than a single desk lamp.
How many hours of use create a noticeable monthly cost?
Hourly cost becomes easier to compare over a month. One 10-watt LED used for 5 hours daily runs about 150 hours in a 30-day month. At $0.20 per kWh, that is 1.5 kWh, or $0.30. A 60-watt incandescent used for the same schedule consumes 9 kWh and costs $1.80.
One bulb usually has a small monthly energy charge, but frequently used fixtures and many bulbs can add up. Ten 10-watt LEDs operating 5 hours a day would cost about $3 per month at $0.20 per kWh. Ten 60-watt incandescent bulbs used on the same schedule would cost about $18. Actual schedules vary, so these examples are usage estimates rather than fixed bills.
To estimate a different schedule, multiply watts by hours of use, divide by 1,000, and multiply by the kWh rate. For a 40-watt fixture used 4 hours daily: 40 × 120 ÷ 1,000 equals 4.8 kWh per month. At $0.18 per kWh, its estimated energy charge is about $0.86 monthly.
Does the U.S. electricity rate change light costs by region?
Yes. Residential electricity rates vary widely across states and utilities, so the same bulb can have different hourly costs. A 60-watt bulb costs about $0.007 per hour at $0.12 per kWh, $0.012 at $0.20, and $0.018 at $0.30. These examples illustrate rate effects; they are not guaranteed prices for any state or city.
Use the rate shown on the household’s bill or utility account for the closest estimate. Some plans have time-of-use pricing, where electricity costs more during specific hours. If a household has such a plan, the relevant rate is the one applying when the light is used. A flat monthly charge should not be treated as an added hourly lighting cost unless calculating the entire bill.
For a more accurate number, look for the energy charge per kWh and any time-based rate details. If the bill lists separate supply and delivery charges per kWh, add those variable charges together. A rough estimate based only on a state average may miss a local utility’s rate or a household’s specific plan.
How to lower the light bill without losing needed brightness
The largest controllable saving is usually replacing heavily used incandescent or halogen bulbs with LEDs that provide comparable lumens. A 10-watt LED used 5 hours a day can save about 7.5 kWh per month compared with a 60-watt incandescent. At $0.20 per kWh, that is roughly $1.50 per month per replaced bulb. The savings are smaller for a light used only occasionally.
Prioritize bulbs with long daily run times, then compare brightness, wattage, and purchase price before replacing everything. Turning off lights in unoccupied rooms can help, but there is little value in repeatedly switching off a bulb that is needed. Occupancy sensors or timers may reduce unnecessary run time in garages, hallways, and outdoor areas; their purchase price and standby draw should be weighed against expected use.
Choose a dimmable LED only when the fixture has a compatible dimmer, and avoid paying extra for features that do not affect the intended use. For outdoor lighting, motion activation or a shorter timer can reduce hours of operation. No installation is needed to calculate a bulb’s running cost: its wattage, time switched on, and the applicable kWh rate are enough.