LED Bulb Savings Calculator

It multiplies the wattage you save per bulb (old watts minus LED watts) by your daily run time and the number of bulbs to get kilowatt-hours saved per year, then multiplies by your electricity rate for the dollar figure. The formula is (old watts minus LED watts) divided by 1,000, times hours per day, times 365, times the number of bulbs, times your price per kWh. It then adds the money you save by replacing burned-out bulbs far less often.

It depends on how many bulbs you swap, how long they run, and your local rate. A single 60W incandescent replaced by a 9W LED running 3 hours a day saves roughly 56 kWh and about $9 to $10 a year at average US rates. Swap ten of them and you approach $100 a year before counting the bulbs you no longer buy, and high-use fixtures like porch lights pay back fastest.

Match brightness in lumens, not watts. A 40W incandescent is about 450 lumens (a 6 to 9W LED), a 60W is about 800 lumens (an 8 to 12W LED), a 75W is about 1,100 lumens (a 9 to 15W LED), and a 100W is about 1,600 lumens (a 14 to 20W LED). Check the lumens line on the package and pick an LED with a similar number.

It divides what you pay for the LED bulbs today by your combined annual savings, both the lower energy use and the bulbs you no longer replace. With inexpensive LEDs and steady use, payback is often only a few months. This is a simple estimate, not financial advice, and it ignores inflation, utility rebates, and changing electricity rates.

Yes. A typical incandescent is rated near 1,000 hours, while LEDs are rated from 15,000 up to 50,000 hours, so one LED can outlast 15 to 25 incandescent bulbs. The calculator turns each bulb's rated life into how many you buy per year, then credits you for the difference. Over an LED's life, that replacement saving can rival the energy saving.

No, they are estimates. Your real savings depend on your actual run time, your all-in electricity rate including taxes and fees, and how each bulb is rated and used. Treat the output as a planning guide rather than a guaranteed figure or financial advice.