LED Bulb Savings Calculator

Calculate how much you save by switching from old bulbs to LED. See payback period and annual savings.

Source: Energy Saving Trust — Lighting

Konstantin Iakovlev

By Konstantin Iakovlev · Founder, Calks.uk

Last updated: · Verified against HMRC and GOV.UK 2026/27 rates

Annual Saving

£232.51

949 kWh saved · Payback: 1.5 months

Old Cost/Year

£268.28

LED Cost/Year

£35.77

LED Purchase

£30.00

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

LED bulbs use 75-85% less electricity than traditional incandescent bulbs and 50-60% less than halogen bulbs for the same brightness. A 10W LED produces the same light (800 lumens) as a 60W incandescent or 42W halogen bulb. LEDs also last 15,000-25,000 hours compared to 1,000 hours for incandescents.

At current electricity rates of 24.5p per kWh, replacing a 60W incandescent bulb used 4 hours daily with a 10W LED saves £17.90 per year. If you have 20 bulbs in your home, switching them all to LED could save over £350 per year. The upfront cost of LED bulbs (£2-£8 each) is recouped within a few months.

This calculator estimates your savings from switching to LED bulbs throughout your home. Enter the number and type of your current bulbs (incandescent, halogen, or CFL), their wattage and average daily usage to see the annual saving, payback period and total savings over the lifespan of the LED replacements.

LED vs incandescent — the dramatic savings. 10W LED replaces 60W incandescent (same light output ~800 lumens). Electricity cost over 25,000 hours at 25p/kWh: LED £62.50; incandescent £375. Savings £312 per bulb over lifetime. LED bulb cost: £3-£8 each. Incandescent cost: £1-£2 each but lasts 1,000 hours (5 needed for 25,000 hours = £5-£10). Total savings per replacement: £300+ over lifetime. UK average home: 30+ light fittings × £300 = £9,000+ lifetime savings.

LED lifespan and quality factors. Quality LEDs: 25,000-50,000 hours (typical UK 20-40 years home use). Cheap LEDs: 5,000-15,000 hours (4-8 years). Look for: L80 rating (80% brightness after 25,000 hours), 5-year manufacturer warranty (Philips, Osram, Crompton), CRI 80+ (colour rendering — natural look). Avoid: unbranded eBay/AliExpress bulbs (often 1,000-3,000 hour life). Colour temperature: 2700K warm (cosy living rooms), 4000K neutral (kitchens, bathrooms), 6500K daylight (workshops, retail).

UK electricity savings from LED upgrade. Average UK home pre-LED: 800-1,200 kWh/year on lighting alone. Post-LED: 80-150 kWh/year. Savings: 700+ kWh/year × 25p = £175/year. Heavy-use homes (lights on long hours): £250-£400/year. Plus reduced heat output: less air conditioning needed in summer (marginal in UK). Payback: typically 12-24 months on replacement bulb cost. ROI on LED upgrade: 100-200% over 5 years.

Smart LED bulbs and ecosystems. Philips Hue: premium ecosystem, £15-£35/bulb, requires hub £40-£60, controls via app, voice assistant integration. IKEA Tradfri: budget smart bulbs £8-£15. LIFX, Govee: WiFi direct (no hub), £12-£25. Sengled, Yeelight: budget alternatives. Smart bulb benefits: voice control, scheduling, dimming, colour change, away-mode. Power consumption while 'off' but connected: 0.3-0.5W per bulb — adds up with 20+ bulbs (£8-£15/year standby cost). Worth it for: scheduling, security, accessibility.

LED downlights and fittings. GU10 LED spotlight: replaces 50W halogen with 5W LED — 10× efficiency. Cost £4-£10/bulb. Common in kitchens, bathrooms. IP rating: IP65 for bathrooms (water-resistant). Dimmable LEDs: check compatibility with dimmer switch (most modern LED dimmers leading-edge). Building Regulations Part L: new builds and major refurbs require LED lighting fitted from 2022. Older fittings: bayonet or screw (B22, E27) — most LED bulbs available in both. Smart switches: replace standard switches (£15-£40), control any bulb voicely or via app.

Example: Replacing 15 halogen downlights (50W each)

  1. Current halogen usage: 15 x 50W x 4 hours/day = 3 kWh/day
  2. Annual halogen cost: 3 x 365 x 24.5p = £268.28
  3. LED replacement (5W each): 15 x 5W x 4 hours = 0.3 kWh/day
  4. Annual LED cost: 0.3 x 365 x 24.5p = £26.83
  5. Annual saving: £241.45
  6. LED bulb cost (15 x £4): £60, payback: 3 months

Source: Energy Saving Trust — Lighting

Frequently Asked Questions

What does the LED Bulb Savings Calculator do?
Calculate how much you save by switching from old bulbs to LED. See payback period and annual savings.
Does this reflect the current energy price cap?
This calculator uses representative energy prices. The Ofgem energy price cap changes quarterly — check Ofgem's website for the latest cap level applicable to your region and payment method.
Can I save money by switching tariff?
Potentially yes. The energy market offers various fixed and variable tariffs. Use a comparison site authorised by Ofgem (such as Ofgem's own comparison tool) to check if switching could save you money.