LED Upgrade Payback Calculator
Calculate when an LED upgrade pays for itself.
Enter old bulb wattage, LED wattage, daily hours, electricity rate, and bulb cost to find the payback period.
LEDs have gotten cheap. A quality A19 LED bulb now costs $1-3. That makes the payback period surprisingly short — often under a month for bulbs running several hours a day.
The math
Annual energy savings (kWh) = (old_watts - led_watts) / 1000 x hours_per_day x 365
Annual savings ($) = kWh_savings x electricity_rate
Payback (months) = led_cost / (annual_savings / 12)
Where the savings are real
A 60W incandescent replaced by a 9W LED saves 51 watts. Running 5 hours per day, that is 93 kWh per year. At $0.13/kWh, that is $12 saved annually per bulb. A $2 LED pays back in 2 months.
Halogen replacements are smaller but still meaningful. A 50W halogen replaced by a 6W LED saves 44 watts. For a house with 20 recessed cans running 4 hours per day, that is over $150 in annual savings.
CFL vs LED is a closer comparison. CFLs already saved energy versus incandescent, so the gap is smaller. But LEDs still win on lifespan: LEDs rated at 25,000 hours vs 8,000 for a typical CFL. In high-use fixtures, that means one LED outlasts three CFLs.
Lifespan in the math
At 5 hours per day, a 25,000-hour LED bulb lasts about 13.7 years. Over that time, you would replace roughly 3 incandescents (1,000 hours each) or 1-2 CFLs. The bulb-replacement cost difference adds further to LED savings, especially in hard-to-reach fixtures.
The biggest savings come from the bulbs that run the most hours. Start with kitchen, living room, and outdoor lights before worrying about the closet.