★ COST COMPARISON · EVERYDAY · LIGHTING & ENERGY

LED vs Incandescent Cost Calculator

Switching 10 bulbs saves $104.58 a year at the defaults — and the bulbs are barely a tenth of the story. Ten 9-watt LEDs running 3 hours a day use 98.55 kWh a year and cost $16.75 of electricity plus $1.31 of bulbs, or $18.06 in total. Ten 60-watt incandescents use 657 kWh and cost $111.69 of electricity plus $10.95 of bulbs, or $122.64 in total. Over ten years the saving is $1,045.80. Enter your own bulb count, hours, rate, wattages, prices, and lifespans below to price your own house.

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What does your lighting really cost each year?

An incandescent bulb turns most of its electricity into heat and only a sliver into light, so it needs roughly seven times the wattage of an LED for the same brightness — and then it burns out roughly twenty-five times sooner, so you keep buying replacements. Both costs land in the same annual total: electricity plus bulbs. Pricing them together is the only honest comparison, because the cheaper bulb at the store is the expensive bulb on the bill.

Number of bulbs

Bulbs in the comparison. Every bulb adds the same energy and replacement cost, so doubling bulbs doubles the saving.

Hours per day

Hours per day. At 6 hours a day the saving jumps to $209.14 a year, because every hour is paid for twice over on the incandescent side.

Electricity rate ($/kWh)

Dollars per kWh. This is the single biggest lever: expensive power punishes the 60-watt bulb far more than the 9-watt one.

LED wattage (W)

LED watts. A 9-watt LED replaces a 60-watt incandescent at similar brightness; brighter LEDs use more, but still far less than incandescents.

Incandescent wattage (W)

Incandescent watts. Swapping the 60-watt bulb for a 100-watt one pushes the incandescent total to $197.10 and the saving to $179.04.

LED bulb price ($)

Dollars per LED bulb. Even at $3.00 each, LEDs cost only $1.31 a year in replacements at the defaults, because they rarely burn out.

Incandescent bulb price ($)

Dollars per incandescent bulb. At $1.00 each, replacements still cost $10.95 a year at the defaults — nearly eleven bulbs a year for ten sockets.

LED life (hours)

LED rated life in hours. A longer life means fewer replacements; even a short-lived 15,000-hour LED barely moves the yearly bulb cost.

Incandescent life (hours)

Incandescent rated life in hours. At 1,000 hours, ten bulbs burning 3 hours a day need 10.95 replacements a year — the hidden half of the bill.

Annual saving with LEDs$104.58Ten bulbs at 3 hours a day use 1,095 hours a year each. LEDs at 9 W use 98.55 kWh costing $16.75, plus $1.31 of bulbs, for $18.06 a year. Incandescents at 60 W use 657 kWh costing $111.69, plus $10.95 of bulbs, for $122.64 a year. The saving is $104.58 a year, or $1,045.80 over ten years.

LEDs save $104.58 a year. LEDs cost $18.06 a year and incandescents cost $122.64 a year at the defaults; over ten years the saving is $1,045.80.

The model, stated exactly

Hours per year = hours per day × 365. Annual kWh for each type = bulbs × watts × hours per year ÷ 1000. Annual energy cost = kWh × electricity rate per kWh. Bulbs replaced per year = bulbs × hours per year ÷ rated life in hours. Annual bulb cost = bulbs replaced × price per bulb. Annual total = energy cost + bulb cost. Saving = incandescent total − LED total; a negative saving means incandescents win, which happens only at implausible inputs. Line items are rounded to cents first and totals are the sums of those rounded lines, so the printed lines always add up exactly ($16.75 + $1.31 = $18.06; $111.69 + $10.95 = $122.64). The model assumes both bulb types give the same light and run the same hours; it does not count the heat an incandescent adds to a room, which slightly helps in winter and hurts in summer, nor dimmer or fixture costs.

The worked example, line by line

Setup: 10 bulbs, 3 hours a day, $0.17/kWh, 9 W LED, 60 W incandescent, $3.00 LED, $1.00 incandescent, 25,000-hour LED life, 1,000-hour incandescent life.

Line 1 — hours per year. 3 × 365 = 1,095 hours per bulb per year.

Line 2 — annual kWh. 10 × 9 × 1,095 ÷ 1000 = 98.55 kWh LED; 10 × 60 × 1,095 ÷ 1000 = 657 kWh incandescent.

Line 3 — energy cost. 98.55 × $0.17 = $16.75 LED; 657 × $0.17 = $111.69 incandescent.

Line 4 — bulbs replaced per year. 10 × 1,095 ÷ 25,000 = 0.438 LED; 10 × 1,095 ÷ 1,000 = 10.95 incandescent.

Line 5 — bulb cost. 0.438 × $3.00 = $1.31 LED; 10.95 × $1.00 = $10.95 incandescent.

Line 6 — annual totals. $16.75 + $1.31 = $18.06 LED; $111.69 + $10.95 = $122.64 incandescent.

Line 7 — the saving. $122.64 − $18.06 = $104.58 a year; over ten years, $1,045.80.

Try these

Just 5 bulbs. LEDs cost $9.04 a year and incandescents $61.33, so even a half-house switch saves $52.29 a year.

6 hours a day. LEDs cost $36.14 a year and incandescents $245.28, so hard-used lights save $209.14 a year — swap the kitchen and living room first.

Expensive electricity: $0.30 per kWh. LEDs cost $30.88 a year and incandescents $208.05, so the saving grows to $177.17 a year.

100-watt incandescents (LED still 9 W). Incandescent energy rises to 1,095 kWh costing $186.15, the incandescent total to $197.10, and the saving to $179.04 a year. Note this branch keeps the 9-watt LED for comparability; a true 100-watt equivalent LED would use about 14 watts, which would still save nearly as much.

Ten years at the defaults. The saving compounds to $1,045.80 — more than the cost of replacing every bulb in the house several times over, before counting the avoided trips up the ladder.

Output · formula · meaning

Output	Formula	What it means
Hours per year	Hours per day × 365	1,095 at the defaults — how long each bulb burns annually.
Annual kWh (each)	Bulbs × watts × hours per year ÷ 1000	98.55 LED, 657 incandescent — the energy gap is the whole story.
Energy cost (each)	kWh × $/kWh	$16.75 LED, $111.69 incandescent.
Bulbs replaced per year	Bulbs × hours per year ÷ rated life	0.438 LED, 10.95 incandescent — the replacement treadmill.
Bulb cost (each)	Bulbs replaced × price per bulb	$1.31 LED, $10.95 incandescent.
Annual total (each)	Energy cost + bulb cost	$18.06 LED, $122.64 incandescent.
Annual saving	Incandescent total − LED total	$104.58 at the defaults — positive means LEDs win.
Ten-year saving	Annual saving × 10	$1,045.80 at the defaults, before any rate rises.

Who uses this

The homeowner staring at a $3 LED next to a $1 incandescent: enters 10 bulbs and learns the $2 sticker gap buys a $104.58-a-year saving — the shelf price is the least important number in the store.
The landlord swapping bulbs between tenants: enters the building's bulb count and hours to show the payback lands in weeks, not years, and the next tenant never calls about a dead bulb.
The renter who can only change bulbs, not fixtures: enters just 5 bulbs and still finds $52.29 a year — a saving that moves out with them in a box.
The household on a high electricity rate: enters $0.30 per kWh and sees the saving jump to $177.17 a year, which makes the kitchen and porch lights the first, not the last, swap.

Accuracy & limitations

The comparison is exact for the numbers you enter, but two inputs deserve a second look. First, equal brightness is assumed: a 9-watt LED genuinely matches a 60-watt incandescent in lumens, but if your LEDs are brighter or dimmer than the bulbs they replace, the energy gap moves with them — match lumens, not watts, when you shop. Second, rated life is a laboratory figure; real bulbs die early from heat, vibration, and enclosed fixtures, and LEDs in particular lose life in hot, enclosed cans. The model also ignores the small heating effect: incandescent waste heat slightly cuts winter heating bills and slightly raises summer cooling bills, but the effect is far smaller than the $104.58 gap. Error policy: missing, non-numeric, or non-positive inputs (bulbs, hours, wattages, prices, lifespans) and a negative electricity rate are reported as errors rather than calculated, so no result ever shows NaN.

Cite this calculatorBright Side Kit. “LED vs Incandescent Calculator 2026 — Bright Side Kit.” brightoolbox.com, 2026.

Bright Side Kit. "LED vs Incandescent Calculator 2026." https://brightoolbox.com/led-vs-incandescent-lighting/ Accessed October 24, 2026.

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Frequently asked questions

How much do LEDs save vs incandescents per year?

$104.58 a year at the defaults: 10 bulbs, 3 hours a day, $0.17 per kWh, 9-watt LEDs against 60-watt incandescents. LEDs cost $18.06 a year in total; incandescents cost $122.64. Over ten years the saving is $1,045.80.

Why are LEDs so much cheaper to run?

Because they need about one-seventh the wattage for the same light, and they last about twenty-five times longer. A 9-watt LED replaces a 60-watt incandescent, so the energy bill falls from $111.69 to $16.75 — and the replacement bill falls from $10.95 to $1.31 on top of that.

Is a 9-watt LED really as bright as a 60-watt incandescent?

Yes, in lumens: both give roughly 800 lumens, the standard brightness for an everyday room bulb. Shop by lumens, not watts. A bulb labeled 800 lumens is the 60-watt replacement whatever its wattage; a dimmer or brighter LED changes the energy math accordingly.

How long does an LED bulb last?

The default rated life is 25,000 hours — over 22 years at 3 hours a day. Real life is shorter in hot, enclosed fixtures, but even a bulb that dies at half its rated life still costs only about $2.63 a year in replacements at the defaults.

How often do incandescent bulbs burn out?

At the defaults, about 11 times a year across 10 bulbs. A 1,000-hour bulb burning 3 hours a day lasts under a year, so a houseful of incandescents is a standing chore as well as a standing cost.

Do LEDs pay for themselves?

Almost immediately at the defaults: the $20 extra spent on 10 LEDs at $3 against $1 each is repaid in about ten weeks of the $104.58 annual saving. After that the saving is pure gain, and the ten-year figure of $1,045.80 assumes electricity never gets more expensive.

What if my electricity is expensive?

The saving grows: at $0.30 per kWh, LEDs cost $30.88 a year and incandescents $208.05, a $177.17 saving. High-rate households gain most from swapping the longest-burning lights first.

Are there lights where incandescents still make sense?

A few: oven lights, where LED electronics cannot take the heat, and some specialty dimming or enclosed-fixture cases. For ordinary room, porch, and kitchen lighting, the LED wins on energy, replacements, and total cost at any plausible rate.