LED vs Halogen Bulb Cost Calculator

Compare LED and halogen electricity costs for the same lighting hours. Add the upfront replacement cost to estimate how long energy savings would take to cover it.

How to use LED vs Halogen Bulb Cost Calculator

1. Choose the currency used for results. 2. Choose comparable light output, enter watts per bulb and the number of bulbs, then add your usage hours and total replacement cost. 3. Change a value to update the results, or select Calculate. Review the chart and notes with the total. 4. Use Copy results, Share results or Download result graphic to keep the answer. Shared links include your figures. 5. Reset restores the editable example inputs.

Why use this tool?

Lighting is a repeated cost: a small difference per evening can add up across several bulbs and a year of use. The calculator shows the annual electricity difference before comparing it with the money spent on replacements. A fair comparison needs similar useful light, not merely two bulbs that fit the same socket. Check brightness and compatibility, especially where there is a dimmer or a particular fitting. Those checks are separate from the cost arithmetic.

How the calculation works

Annual electricity cost = watts per bulb ÷ 1,000 × bulb count × hours per day × days used × unit price. Annual saving = halogen cost − LED cost. Simple replacement payback = upfront replacement cost ÷ positive annual saving. The model excludes replacement frequency, bulb lifespan and changing tariffs. If the proposed LED setup has no positive energy saving, an energy-saving payback is not shown.

Example

Six 50 W halogen bulbs used for four hours a day over 365 days use 438 kWh. Six 5 W LEDs use 43.8 kWh. At an illustrative £0.25/kWh, the annual difference is £98.55. A £30 replacement cost has a simple payback of about 0.30 years under those assumptions.

Practical tip

Use the cost of replacing the full set you are comparing. If the fitting also needs replacing, include that in the upfront cost.