UK LED Lighting Cost Calculator — Annual Savings & Payback

Use our UK LED cost calculator to work out exactly how much you can save by switching from halogen or incandescent bulbs to LED. Enter your current bulb wattage, the LED replacement wattage, and how many hours per day you use the light. The calculator uses the UK average electricity price (27.03p per kWh as of April 2026) and shows your annual cost, total savings, and payback period.

How LED Savings Are Calculated

The calculation is straightforward: multiply wattage by hours of use, then by 365 days, and divide by 1,000 to get kilowatt-hours (kWh) per year. Multiply kWh by the electricity price (in pounds) to get annual running cost. Subtract the LED cost from the halogen cost to get annual savings.

Formula:

• Annual kWh = (Wattage × Hours per day × 365) ÷ 1,000
• Annual cost = Annual kWh × Price per kWh
• Savings = Old cost − New cost
• CO₂ reduction = kWh saved × 0.207 kg (UK grid emissions factor, 2026)

Typical LED Replacement Wattages

Use these equivalents when replacing traditional bulbs with LED:

Halogen / Incandescent	LED Equivalent	Light Output (Lumens)
25W	3–4W	~250 lm
40W	5–6W	~470 lm
60W	8–10W	~800 lm
75W	11–13W	~1,100 lm
100W	14–17W	~1,600 lm
150W	20–25W	~2,600 lm

Payback Period — How Long to Break Even

At UK electricity prices, a standard A60 LED bulb replacing a 60W halogen bulb pays for itself in under 4 months, assuming 5 hours of use per day. Higher-wattage replacements break even even faster because the wattage gap is larger.

Quick examples (based on 5 hours/day, UK average price 27.03p/kWh, £4 LED bulb):

• 40W → 5W LED: Saves £17.27/year. Payback in 2.8 months.
• 60W → 9W LED: Saves £25.14/year. Payback in 1.9 months.
• 100W → 14W LED: Saves £42.41/year. Payback in 1.1 months.
• 150W → 20W LED: Saves £64.12/year. Payback in 0.7 months.

UK Electricity Price Context

UK electricity prices are set quarterly by Ofgem through the Energy Price Cap. As of April 2026, the average unit rate on the price cap is 27.03p per kWh (including VAT at 5%), though rates vary by supplier and tariff. Standing charges are not affected by bulb usage so they are excluded from this calculation.

If you are on a fixed-rate tariff or an Economy 7 meter, use your own unit rate in the calculator for accurate results.

Frequently Asked Questions

How much does it cost to run an LED bulb for a year?

A typical 9W LED bulb used for 5 hours per day costs approximately £4.44 per year at UK average electricity prices (27.03p/kWh). For comparison, the 60W halogen equivalent costs £29.63 per year — a £25.19 annual saving per bulb.

Do LED bulbs really last 25,000 hours?

High-quality LED bulbs are rated for 15,000–25,000 hours of use, which works out to about 14 years at 5 hours per day. Cheaper LEDs may fail sooner — look for CE-certified bulbs from reputable brands to ensure the rated lifespan.

Are dimmable LEDs more expensive to run?

No. Dimmable LEDs use the same wattage as non-dimmable ones at full brightness. When dimmed, they use proportionally less power — a 9W LED dimmed to 50% uses approximately 4.5W.

What is the CO₂ saving from switching to LED?

Replacing one 60W halogen bulb with a 9W LED saves approximately 24 kg of CO₂ per year, based on the UK grid emissions factor of 0.207 kg CO₂/kWh (2026). Across 10 bulbs in a typical home, that is over 240 kg of CO₂ saved annually.

Does LED lighting flicker and is it safe?

Quality LED bulbs are flicker-free thanks to high-frequency drivers. Avoid very cheap LEDs that use basic capacitor drivers — these can cause visible flicker, especially when dimmed. All CE-certified LEDs sold in the UK meet safety requirements for residential use.

Shop LED Lighting at Verthara

Every LED product at Verthara is CE certified, covered by a 3-year manufacturer warranty, and delivered free across the UK. Browse our range:

• LED ceiling lights and fixtures
• Ceiling lights collection
• LED pendant lights
• LED wall lights