LED Bulb Savings Calculator
See how much switching your halogen, incandescent or CFL bulbs to LED saves a year, how many months it takes the bulbs to pay for themselves, and the saving over 10 years.
Estimate only. These are estimates — appliance ratings and tariffs vary, and actual bulb wattage and brightness vary by manufacturer. Check the packaging for the exact wattage and lumens of your bulbs.
| Per bulb / year | Total / year | |
|---|---|---|
| Current bulbs | £13 | £67 |
| LED replacement | £2 | £9 |
Getting the most from an LED switch
- Replace your most-used bulbs first — hallway, kitchen and living room lights on for hours a day save far more than a spare-room bulb used for minutes a week.
- Don't wait for an old bulb to fail before switching — the running-cost saving usually beats the cost of the LED well within a year, so replacing early is rarely a loss.
- Compare bulbs by lumens (brightness), not watts — a 7W LED and a 60W incandescent can produce a similar amount of light for a fraction of the running cost.
- LEDs also run cooler and typically last many times longer than halogen or incandescent bulbs, cutting how often you're replacing them as well as what they cost to run.
How the LED bulb saving is calculated
Each bulb's annual running cost comes from its wattage, how many hours a day it's on, and your electricity unit rate: energy used (kWh/year) = watts ÷ 1000 × hours/day × 365, and cost = energy × rate. Comparing your current bulb type against a 7W LED at the same hours of use gives the annual saving per bulb, which scales up by however many bulbs you're replacing. Dividing the up-front cost of the LED bulbs by the annual saving — then converting to months — gives the payback period: how long the LEDs take to cover their own cost before every year after that is pure saving.