Billowatt

LED Light Bulb vs Incandescent Bulb: Which Costs Less to Run?

The most settled matchup in home energy, still worth quantifying because the numbers are so lopsided.

LED Light Bulb · per month

$0.26

5 hours/day · 5–15 W

Incandescent Bulb · per month

$1.71

5 hours/day · 40–100 W

Verdict

LED wins by roughly 85% per bulb — 9 watts doing the work of 60 — and lasts 15–25× longer. A whole-house conversion typically pays for itself within months. There is no scenario in which buying new incandescents makes financial sense; the only question left is how quickly you replace the survivors.

Side by side

LED Light Bulb Incandescent Bulb
Typical power5–15 W40–100 W
Typical usage5 hours/day5 hours/day
Energy per month1.4 kWh9.1 kWh
Cost per month (US avg)$0.26$1.71
Cost per year (US avg)$3.09$20.59
Cost per month in Hawaii$0.64$4.25

Rates as of April 2026. Adjust the assumptions on each appliance's page: LED Light Bulb · Incandescent Bulb.

Frequently asked questions

Which is cheaper to run: a led light bulb or a incandescent bulb?

At typical usage and the current U.S. average rate (18.8¢/kWh), the led light bulb is cheaper: about $0.26/month versus $1.71/month for the incandescent bulb — a difference of $1.46 per month.

How much could I save per year by choosing the led light bulb?

About $17.49 per year at typical usage and average rates. In Hawaii (46.6¢/kWh) the annual gap grows to roughly $43.35.

Do these numbers apply to my state?

The ratio between the two stays the same everywhere, but the dollar gap scales with your rate — from North Dakota at 12.4¢/kWh to Hawaii at 46.6¢/kWh. Open each appliance's page for the exact cost in your state.