LED vs Incandescent Savings Calculator
Thinking about swapping old bulbs for LEDs? Our free LED vs incandescent savings calculator compares the yearly kWh, energy cost and 10-year savings of your old bulbs against LED replacements — plus how fast the new bulbs pay for themselves.
Enter your numbers
Default is a national-average estimate — rates vary by utility and plan, so use your bill for best accuracy.
Your results
Planning estimate. Assumes steady daily use and a flat electricity rate. Bulb prices and rates are estimates — adjust them to match your situation.
| Yearly energy — old bulbs | — |
| Yearly energy — LEDs | — |
| Yearly cost — old bulbs | — |
| Yearly cost — LEDs | — |
| Energy reduction | — |
| Payback period | — |
CO₂ note: this is an estimate — about 0.85 lb of CO₂ is avoided per kWh of lighting energy saved (US grid average).
How to use this calculator
Start with how many bulbs you want to replace, then enter the wattage printed on your old bulbs (60W is the classic incandescent) and on the LED replacements you're considering (9W is a common LED equivalent). Next, set how many hours a day the lights are on and your electricity rate per kWh.
If you know what each bulb costs, fill in the two optional price fields and the calculator will tell you how fast the LEDs pay for themselves. Leave them blank and the payback row simply disappears — the energy savings still show.
Everything recalculates instantly as you type, so you can test scenarios: what if the LEDs run 6 hours a day instead of 3, or your rate is $0.25 instead of the default estimate? With the defaults — ten 60W bulbs swapped for 9W LEDs at $0.17/kWh — you save about $94.94 a year.
How it works
The math is simple energy bookkeeping. For each bulb type: kWh per year = bulbs × (watts ÷ 1,000) × hours per day × 365. Then yearly cost = kWh per year × electricity rate. Savings are just the old cost minus the LED cost, and 10-year savings multiply that by 10.
Payback compares upfront costs: extra upfront cost = (LED price − old price) × bulbs, then payback (years) = extra upfront cost ÷ yearly savings. If the LEDs cost the same or less than replacements, payback is effectively instant.
A note on lifespan: quality LED bulbs are commonly rated for 15,000–25,000 hours versus about 1,000 for an incandescent, so over its life one LED can replace roughly 15–25 old bulbs — replacement savings the calculator doesn't even count. The CO₂ note uses a labeled estimate of about 0.85 lb of CO₂ per kWh saved (US grid average); the default $0.17/kWh rate is likewise a national-average estimate, since rates vary widely by utility, state and plan.
Frequently asked questions
How much can I save by switching to LED bulbs?
A typical 60W incandescent swapped for a 9W LED uses 85% less energy, so ten bulbs used 3 hours a day at an average rate of $0.17 per kWh save about $95 a year. Enter your actual bulb count, hours and rate above to get your own number.
How long do LED bulbs really last?
Quality LED bulbs are commonly rated for 15,000 to 25,000 hours, while an incandescent is rated for roughly 1,000 hours. That means one LED can replace about 15 to 25 incandescents over its life, which adds to the savings on replacements. Actual lifespan varies by brand, heat and usage.
What does the payback period mean?
The payback period is how long the yearly energy savings take to cover the higher upfront cost of the LED bulbs. For example, if the LEDs cost $20 more than replacements and save $95 a year, payback is about 2.5 months. Fill in the optional bulb costs above to see yours.
Why is my electricity rate labeled an estimate?
Electricity rates vary by utility, state, time-of-use plan and taxes, so the default $0.17 per kWh is a national average used as a starting estimate. Check your latest bill for your real all-in rate and enter it above for a more accurate result.
How much CO2 do LED bulbs save?
This calculator uses a rough factor of about 0.85 lb of CO2 per kWh saved, a common estimate for the US grid average. Ten 60W bulbs swapped for 9W LEDs used 3 hours a day avoid roughly 475 lb of CO2 per year. It is a labeled estimate, not a measured value.