LED Bulb Savings Calculator

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

Last updated: April 2026 · Source: Energy Saving Trust — Lighting

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.

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. All calculations are performed in your browser using official UK rates and thresholds.
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.