LED Lighting Savings Calculator — Replace Incandescent & Halogen Bulbs
Calculate annual savings from switching to LED bulbs. Enter number of bulbs, old wattage and usage hours to see payback period, 10-year savings and CO₂ reduction.
How to use this calculator
- Enter the number of bulbs you plan to replace — count every incandescent and halogen bulb in your home.
- Set the old bulb wattage (typically 40W, 60W, 75W or 100W incandescent; 35W or 50W halogen spotlights).
- Set the LED replacement wattage — typically 6–10W replaces a 60W incandescent with equivalent brightness.
- Enter average hours used per day across all bulbs (home average is 3–5 hours).
- Enter your electricity rate and LED bulb cost to see payback, annual savings and CO₂ reduction.
Understanding your results
How LED savings are calculated: Each bulb saves (old wattage − LED wattage) watts. Multiply by hours per day × 365 days × number of bulbs to get annual kWh saved. Multiply by your electricity rate to get annual dollar savings.
Typical example: Replacing 20 × 60W incandescent bulbs with 9W LEDs, used 4 hours/day, saves: 20 × (60−9)/1000 × 4 × 365 = 1,489 kWh/year. At $0.163/kWh, that is $243/year saved. 20 LED bulbs at $4 each cost $80, giving a 4-month payback.
Lumens vs watts: LEDs are measured in lumens (light output), not watts (energy consumption). A 60W incandescent produces about 800 lumens. A 9–10W LED produces the same 800 lumens. Always match lumens, not watts, when selecting LED replacements.
Color temperature matters: LEDs come in warm white (2700K — matches incandescent), cool white (4000K — office/kitchen) and daylight (5000–6500K — task lighting). Mixing temperatures in the same room looks inconsistent. For living areas, stick with 2700K warm white for the most comfortable light quality.
IRA incentive: The Inflation Reduction Act does not provide direct rebates for LED bulbs, but many utilities offer $1–$3 per LED bulb rebates through their efficiency programs. Check DSIRE or your utility’s website for available LED rebates in your area.
Frequently asked questions
Direct answers for US homeowners.