LED Savings Calculator UK
See how much you could save by switching to LED light bulbs with our free UK savings calculator. Enter the number of bulbs you want to replace, your current bulb type (incandescent, halogen or CFL), the LED equivalent wattage and how many hours per day they are used. The calculator shows your annual energy savings, the cost of the LED bulbs and how quickly the switch pays for itself.
Lighting accounts for around 11% of the average UK electricity bill. Switching from old incandescent or halogen bulbs to LEDs is one of the simplest and most cost-effective ways to reduce your energy costs. A 9W LED produces the same light as a 60W incandescent bulb while using 85% less electricity. For a home with 10 bulbs used 5 hours a day, the annual saving can exceed £45. LEDs also last up to 25,000 hours, meaning fewer replacements and less hassle over time.
Why LEDs Are the Most Efficient Lighting Option
LED (Light Emitting Diode) technology has revolutionised home lighting. Unlike incandescent bulbs, which waste 90% of their energy as heat, LEDs convert the vast majority of electricity directly into light. A modern 9W LED produces the same 800 lumens of brightness as a traditional 60W incandescent bulb, cutting energy consumption by 85%. Even compared to CFL (compact fluorescent) bulbs, LEDs are around 35% more efficient and reach full brightness instantly without the warm-up delay.
The UK Government phased out the sale of halogen bulbs in 2021, encouraging households to switch to LEDs. According to the Energy Saving Trust, if every UK household replaced all remaining halogen bulbs with LEDs, the national energy saving would be equivalent to the output of three power stations. For more on energy efficiency initiatives, visit the Ofgem environmental schemes page.
Choosing the Right LED Bulb
When shopping for LEDs, focus on lumens (brightness) rather than watts (energy consumption). An 800-lumen LED replaces a 60W incandescent, while a 1,400-lumen LED replaces a 100W bulb. Colour temperature is measured in Kelvin: 2,700K gives a warm white similar to incandescent bulbs, 4,000K is a cooler daylight tone popular in kitchens and bathrooms. If you have dimmer switches, ensure you buy bulbs specifically labelled as dimmable and consider a trailing-edge dimmer switch for flicker-free performance.
Quality LEDs from reputable brands last 15,000 to 25,000 hours, compared to just 1,000 hours for incandescent and 2,000 hours for halogen. This means fewer replacements and less waste over time. For a broader view of your electricity spending, use our electricity cost calculator to see how lighting fits into your total bill, or try the appliance running cost calculator to compare lighting against other household devices.
The Environmental Impact of Switching to LEDs
Beyond cost savings, switching to LEDs reduces your carbon footprint. Each kWh of electricity saved prevents approximately 0.233 kg of CO2 emissions based on the current UK grid mix. A household replacing 15 incandescent bulbs with LEDs could save over 50 kg of CO2 per year. LEDs also contain no mercury, unlike CFL bulbs, making them safer to dispose of and better for the environment.
Yes. A 42W halogen replaced by a 9W LED cuts energy use by nearly 80%. With bulbs costing as little as £3, you recoup the cost within a few months and then enjoy years of savings.
A 9W to 10W LED produces roughly 800 lumens — the same as a 60W incandescent. For 100W, look for 14–15W LEDs (1,400+ lumens). Always check the lumen rating.
Only if specifically labelled as dimmable. You may also need a trailing-edge dimmer switch designed for low-wattage LED loads. Check both bulb and dimmer compatibility before purchasing.
Most quality LEDs are rated for 15,000 to 25,000 hours. At 5 hours daily, that is 8 to 14 years. Halogen bulbs last around 2,000 hours (about 1 year), and incandescent around 1,000 hours (about 6 months).
This calculator provides estimates for guidance only. Actual savings depend on your electricity tariff, bulb wattages and usage patterns. This is not financial, legal or professional advice. For information on energy tariffs, visit Ofgem.