LED Savings Calculator
See what switching to LED bulbs saves per year.
Results update as you type.
How it works
LED bulbs produce the same light as old incandescent bulbs while drawing a fraction of the power, so replacing them cuts both electricity use and bills. This LED savings calculator quantifies the switch: enter how many bulbs you are replacing, the old and new wattages, daily hours of use, and your electricity rate, and it returns the kilowatt-hours and money you save each year. The saving comes from the wattage gap. A traditional 60-watt bulb and a 9-watt LED give similar brightness, but the LED uses roughly 85 percent less energy. Across many bulbs burning several hours a day, those watts add up to real kilowatt-hours, and at typical electricity rates the annual saving often exceeds the cost of the bulbs themselves within the first year. Beyond the money, LEDs last far longer, meaning fewer replacements and less waste, and they run cooler, easing summer cooling loads. Seeing the yearly figure helps you decide whether to switch all at once or prioritise the bulbs that burn longest. Homeowners cutting utility bills, landlords upgrading rentals, and facility managers lighting large spaces all use an LED savings calculator to justify the upgrade. Because lighting can be a meaningful slice of a home's electricity, the savings shown here compound year after year for the life of the bulbs.
savings = bulbs × (W_old − W_led) ÷ 1000 × hours/day × 365 × rate
Each bulb you switch cuts power draw by the difference between the old and new wattage. Multiplying that watt saving by the number of bulbs and dividing by 1,000 converts it to kilowatts, and multiplying by daily hours and 365 days gives the kilowatt-hours saved across a year. Multiplying those saved kilowatt-hours by your electricity rate turns the energy saving into the annual dollar saving you keep by running LEDs instead of incandescent bulbs.
Source:U.S. Department of Energy lighting efficiency data
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter number of bulbs, old bulb wattage, led wattage, hours used per day and electricity rate.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Annual savings updates instantly as you type — no button to press.
Frequently asked questions
Do LEDs really give the same brightness at lower wattage?
Yes. Brightness is measured in lumens, not watts, and LEDs produce far more lumens per watt than incandescent bulbs. A 9-watt LED typically matches the roughly 800 lumens of a 60-watt incandescent. When shopping, compare lumens rather than watts, and look for the wattage-equivalent label. This efficiency is exactly why the switch saves so much energy while keeping your rooms just as bright as before.
Does this include the cost of buying the LED bulbs?
No, the calculator shows only the electricity savings, not the purchase price of the bulbs. LEDs cost more upfront than incandescent bulbs but far less to run, and they last many times longer. To find payback, divide the total bulb cost by the annual saving shown here. In most homes the electricity saving repays the bulbs within the first year, after which the savings are effectively free.
How much longer do LED bulbs last?
LED bulbs commonly last 15,000 to 25,000 hours or more, compared with about 1,000 hours for a typical incandescent — often 15 to 25 times longer. That means fewer replacements, less packaging waste, and less hassle changing hard-to-reach fittings. The longevity also adds a hidden saving this calculator does not count: the cost of the many incandescent bulbs you would have bought and thrown away over the LED's life.
Which bulbs should I switch first?
Prioritise the bulbs that burn the longest each day, since savings scale directly with hours of use. Kitchen, living room, and outdoor security lights that run for hours deliver far more saving than a closet bulb used for minutes. Run this calculator for your highest-use fixtures first to capture the biggest gains quickly, then replace the rest over time as the old bulbs fail.
Do LEDs help beyond the electricity bill?
Yes. Because LEDs convert more energy into light and less into heat, they reduce the waste heat your bulbs add to a room, easing air-conditioning loads in summer. They also lower your carbon footprint by cutting electricity demand, and their long life means less manufacturing and landfill waste. The financial saving shown here is the most visible benefit, but the environmental and comfort gains add real value too.