LED Savings Calculator
Find out exactly how much money you save each year by replacing incandescent or CFL bulbs with LEDs. Enter wattages, daily usage, and your electricity rate to get an annual dollar figure.
About this calculator
The annual savings from switching to LED bulbs comes down to the difference in power consumption multiplied by how long the lights run and what you pay per unit of energy. The formula is: savings = (oldWatts − newWatts) × hours × 365 × rate / 1000. Dividing by 1,000 converts watt-hours to kilowatt-hours (kWh), which is the unit utility companies use for billing. A typical incandescent 60 W bulb replaced by a 9 W LED saves 51 W per hour of use. Over a year of daily operation that gap compounds into meaningful dollar savings, especially for lights that run many hours a day. The calculation also implicitly captures carbon reduction, since less energy consumed means fewer emissions from the grid.
How to use
Example: replacing a 60 W incandescent with a 9 W LED, used 5 hours per day, at an electricity rate of $0.13/kWh. Step 1 — Wattage difference: 60 − 9 = 51 W saved. Step 2 — Annual energy saved: 51 × 5 × 365 = 93,075 Wh. Step 3 — Convert to kWh: 93,075 / 1,000 = 93.075 kWh. Step 4 — Multiply by rate: 93.075 × $0.13 = $12.10 saved per bulb per year. For a home with 20 such bulbs, total annual savings would be roughly $242.
Frequently asked questions
How much money can I save per year by switching from incandescent to LED bulbs?
The savings depend on wattage difference, daily usage, and your local electricity rate. A single 60 W incandescent replaced by a 9 W LED run for 5 hours daily at $0.13/kWh saves about $12 per year. With dozens of bulbs in a home, whole-house savings commonly range from $150 to $400 annually. Areas with higher electricity rates—like Hawaii or parts of the Northeast—see even larger returns.
What electricity rate should I use in the LED savings calculator?
Use the rate shown on your utility bill, typically listed as cents per kilowatt-hour (¢/kWh). The U.S. national average is around 12–16 ¢/kWh, but rates vary widely by state and provider. You can find your exact rate by dividing your total monthly charge by the total kWh consumed that month. Using an accurate rate gives you the most realistic payback estimate.
How long does it take for LED bulbs to pay back their purchase price?
Most LED bulbs pay back their cost in energy savings within 1 to 3 years, depending on usage hours and electricity rates. A bulb costing $3–$5 that saves $10–$15 per year achieves payback in well under a year for high-use fixtures. LEDs also last 15,000–25,000 hours compared to 1,000 hours for incandescents, so you avoid frequent replacement costs. The combination of energy and replacement savings makes LEDs one of the highest-return home efficiency investments available.