How Much Does It Cost to Run a Light Bulb?
A 9W LED bulb run 5 hours a day costs about $2.63 a year. The old 60W incandescent it replaces costs about $17.52 a year for the exact same brightness — so each LED swap saves roughly $15/year per bulb. At the 2024 US average rate of $0.16/kWh, leaving one incandescent on all day costs about $0.23; the same LED costs about $0.03.
Adjust the wattage, hours, and your electricity rate below — the calculator is preloaded with a 9W LED. To price the incandescent instead, open the incandescent bulb page (preloaded at 60W), or compare lighting against other loads on the efficiency rankings.
Daily Cost
$0.01
0.0 kWh
Monthly Cost
$0.22
1.3 kWh
Yearly Cost
$2.63
16.4 kWh
For perspective...
At $2.63/year, this appliance costs less than a single cup of coffee per month. Not worth worrying about.
The Formula
Cost per day = (watts ÷ 1,000) × hours on × price per kWh
The number printed on a bulb (or in the "=60W" equivalence) is its wattage — the only input that changes between bulb types at the same brightness. Brightness is measured in lumens, not watts, which is why a 9W LED and a 60W incandescent can both put out 800 lumens.
Worked example (9W LED, 5 hours/day, $0.16/kWh): 0.009 kW × 5 h = 0.045kWh × $0.16 = $0.01 per day — or about $2.63/year.
LED vs Incandescent Annual Cost Comparison
All four bulbs below produce about 800 lumens — what people call a "60-watt" bulb. Only the wattage (and therefore the cost) changes. Annual cost assumes 5 hours/day at $0.16/kWh.
| Bulb type (800 lumens) | Watts | kWh per year | Cost per year | vs LED |
|---|---|---|---|---|
| LED (cheapest)Most efficient; 800 lumens at 8-10W | 9W | 16.4 | $2.63 | — |
| CFL (compact fluorescent)Older efficient type, now being phased out | 14W | 25.6 | $4.09 | +$1.46 |
| Halogen incandescentModern halogen 60W-equivalent | 43W | 78.5 | $12.56 | +$9.93 |
| IncandescentTraditional bulb; ~90% of energy is heat | 60W | 109.5 | $17.52 | +$14.89 |
The incandescent burns about $15/year more than the LED for identical light. Factor in bulb life too: an LED lasts 25,000+ hours versus roughly 1,000 for an incandescent, so you also buy 20-25 fewer replacement bulbs over its lifetime.
Cost by Hours On — LED vs Incandescent
A single 9W LED versus a 60W incandescent at $0.16/kWh. The more hours a bulb runs, the bigger the gap.
| Hours per day | LED (9W) / year | Incandescent (60W) / year | You save / year |
|---|---|---|---|
| 2 | $1.05 | $7.01 | $5.96 |
| 4 | $2.10 | $14.02 | $11.91 |
| 5 (typical) | $2.63 | $17.52 | $14.89 |
| 8 | $4.20 | $28.03 | $23.83 |
| 12 (porch / hallway) | $6.31 | $42.05 | $35.74 |
Annual Cost by Rate and Bulb Wattage
One bulb at 5 hours/day across different electricity rates. Find your state on the rates page to pick the right row.
| Rate ($/kWh) | 9W (LED) | 14W | 43W | 60W (incand.) |
|---|---|---|---|---|
| $0.10 | $1.64 | $2.56 | $7.85 | $10.95 |
| $0.13 | $2.14 | $3.32 | $10.20 | $14.24 |
| $0.16 (US avg) | $2.63 | $4.09 | $12.56 | $17.52 |
| $0.20 | $3.29 | $5.11 | $15.70 | $21.90 |
| $0.30 | $4.93 | $7.67 | $23.54 | $32.85 |
Even in high-cost Hawaii or New England (~$0.30/kWh), an LED bulb runs about $4.93/year — less than the same incandescent costs at the cheapest rates in the country.
What Drives the Cost
Bulb technology, not brightness
Two bulbs can both light a room equally (800 lumens) while one draws 60W and the other 9W. An incandescent wastes about 90% of its energy as heat; an LED converts almost all of it to light. The wattage gap is the entire cost story.
Hours on — especially the lights you forget
A porch light, hallway, or closet bulb left on 12+ hours a day costs far more than a lamp you flick on for an hour at night. These "always-on" fixtures are the first ones worth converting to LED or putting on a timer/motion sensor.
How many bulbs are actually running
One bulb is pennies; a whole house is not. A chandelier or vanity bar with 6-10 incandescent bulbs running together is effectively a 360-600W load — more than a refrigerator. Count fixtures, not just bulbs, when you tally lighting cost.
How to Lower the Cost
Swap your high-use bulbs to LED first
Kitchen, living room, and porch bulbs that run for hours save the most. Each 60W → 9W swap is about $15/year.
Put forgotten lights on a sensor
Motion sensors or timers for closets, halls, and porches kill the hours nobody's actually in the room.
Match brightness to the room
You don't need an 800-lumen bulb in a closet. Lower-lumen LEDs draw even less — buy by lumens, not habit.
Dim where you can
A dimmable LED on a compatible dimmer pulls less power the lower you set it — handy in bedrooms and living rooms.
Just turn them off
The "leave them on to save the surge" rule never applied to LEDs. Off is always cheaper if you're leaving the room.
Use daylight before bulbs
Open the blinds. Free light beats any bulb, and it cuts the hours your fixtures run during the day.
Recommended picks
Lighting Picks That Cut the Bill
Lighting savings come from two moves: switch to LED, and stop running lights nobody's using. These picks cover both — efficient bulbs plus the switches and sensors that turn them off automatically.
LED Bulb Multipack (60W equivalent, ~9W)
~$15/yr saved per swapped bulb
An 800-lumen LED replaces a 60W incandescent at 8-10W. Each frequently-used bulb you swap saves roughly $15/year at average rates — and the pack usually pays for itself in months.
Smart LED Bulbs with Schedule
Auto-off the lights left on
Schedules and motion routines turn off lights nobody's using — the single biggest lighting waste. Smart LEDs add only ~0.5W of standby draw, a rounding error on the bill.
LED Dimmer Switch
Less power when dimmed
A dimmable LED on a compatible dimmer pulls less power the lower you set it. Good for living rooms and bedrooms where full brightness is rarely needed.
Motion-Sensor LED Bulbs
Closets, halls, porches
Built-in motion sensors light the space only while someone's there — ideal for closets, hallways, and entryways that get left on for hours by accident.
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Related Guides
LED Bulb Cost Calculator
Prefilled at 9W — tweak hours and your rate
Incandescent Bulb Cost Calculator
Prefilled at 60W — see what the old bulb costs
Most Efficient Appliances
See where lighting ranks against everything else
How to Save on Energy Bills
Practical tips by room with savings
Cost to Run a TV
Another low-watt electronic that adds up
Electricity Rates by State
Find your state's average rate
Frequently Asked Questions
How much does it cost to leave a light on all day?
Leaving a single 60W incandescent bulb on for a full 24 hours uses 1.44 kWh — about $0.23 a day at the US average rate of $0.16/kWh, or roughly $84 a year if you never turned it off. The same brightness from a 9W LED costs only about $0.03 a day — around $13 a year. So an LED left on all day costs pennies, while an old incandescent left on adds up fast.
Do LED bulbs really save money?
Yes. A 9W LED replacing a 60W incandescent at the same brightness uses about 85% less electricity. Run 5 hours a day, the LED costs about $2.63/year versus $17.52/year for the incandescent — a saving of roughly $15 per bulb every year. An LED bulb costs only a few dollars and lasts 25,000+ hours (vs about 1,000 for an incandescent), so it pays for itself in months and then keeps saving for years. Across a whole home of frequently-used bulbs the savings reach $50-$150/year.
How much electricity does a light bulb use?
It depends entirely on the bulb type, not the brightness. For the same 800 lumens (a typical "60-watt" bulb): an LED draws 8-10W, a CFL about 13-15W, a halogen about 43W, and an old incandescent a full 60W. Over 5 hours a day, that's 16 kWh/year for the LED versus 110 kWh/year for the incandescent — the same light for a fraction of the power.
Is it cheaper to leave LED lights on or turn them off?
Turn them off. The old advice about leaving lights on to avoid a startup surge applied to fluorescent tubes, not LEDs. LEDs draw the same power the instant they switch on, have no meaningful inrush cost, and aren't worn out by switching. If you'll be out of a room for more than a few seconds, switching the light off always saves money.
How much can I switch my whole home to LED save?
The US Department of Energy estimates the average home has about 40 light bulbs. You won't save on all of them — savings come from the bulbs you actually use for hours each day (kitchen, living room, porch). Swapping each frequently-used 60W incandescent for an LED saves about $15/year, so converting 10-20 high-use bulbs typically cuts $149-$298 off the annual bill, plus the replacement-bulb savings from LEDs lasting 20-25× longer.
Do LED bulbs use electricity when turned off?
A standard LED on a normal switch uses zero power when off. Smart LEDs and bulbs on dimmers or motion sensors keep a tiny standby draw — usually about 0.3-0.5W to stay connected — which is well under $1/year per bulb and far outweighed by the on-time savings.