LED Energy Savings Calculator
Put a number on an LED swap — the yearly energy and money saved versus your old bulbs, across as many lamps and years as you like.
Your savings
| Energy / yr | Cost / yr | |
|---|---|---|
| LED (1×) | 16.43 kWh | $2.79 |
| Old bulb (1×) | 109.5 kWh | $18.62 |
Energy only — it does not include the purchase price of the bulbs or the fact that LEDs last far longer, both of which usually add to the saving. Use your own tariff for an accurate figure.
Small wattage, big difference
A bulb's running cost is nothing more than the energy it burns times what that energy costs. Energy is power multiplied by time, so a low-wattage LED that produces the same light as a high-wattage incandescent quietly saves money every hour it is switched on. The gap looks small per hour but compounds into real sums over a year of daily use.
Multiply that annual saving by the number of bulbs in the house and the years you keep them and the total grows quickly — before you even count the LED's much longer life and the replacements you avoid buying. This estimate isolates the energy portion so you can see exactly where the saving comes from.
Frequently Asked Questions
How do I calculate a bulb's yearly energy use?
Convert watts to kilowatts and multiply by the hours it runs: kWh per year = (watts ÷ 1000) × hours per day × 365. A 10-watt bulb on for 5 hours a day uses 0.01 × 5 × 365 = 18.25 kWh a year. Multiply by your electricity price for the annual cost.
How much does switching to LED save?
The saving is the wattage difference turned into energy and cost. Replacing a 60-watt incandescent with a 10-watt LED, on 5 hours a day at $0.15/kWh, saves about (109.5 − 18.25) kWh × $0.15 ≈ $13.70 per bulb each year — and that repeats every year the bulb keeps running.
Does this include the price of the bulbs?
No. This compares running energy only. LEDs cost more to buy but last far longer — often 15,000 to 50,000 hours versus around 1,000 for an incandescent — so their real advantage is usually larger than the energy figure alone once purchase and replacement costs are added.
What electricity price should I use?
Use your own tariff from a recent bill, in the same currency, per kilowatt-hour. Rates vary widely by country and provider, so plugging in the real number makes the estimate far more accurate than any default.
Do LEDs really last longer?
Generally yes. Quality LEDs are rated for many times the life of incandescent or halogen bulbs, which means fewer replacements and less waste on top of the energy saving. Lifespan depends on the driver quality and how hot the fitting runs.
Educational estimate of energy cost only, excluding purchase price and bulb lifespan. Use your own electricity tariff for an accurate figure.