The main advantage of upgrading to LED lighting is that the running costs are significantly lower than traditional lighting such as halogen or incandescent. These savings could be up to 90%. This being said though, do you know the actual cost to run LED bulbs? Today we going to answer this question.

How do you work out the cost of electricity?

Before we can work out the cost of running an LED bulb we first should look at how the cost of electricity is worked out. Mains electricity is measured kilowatt hours (kWh) so the more kWh you use the more you will pay. The actual cost can be worked out as follows:


Your cost per kWh will depend on your provider. This could be up to 17p if you pay quarterly (rather than by direct debit), so we will use an average of 14p for this article.

Different electrical appliances individually use different amounts of electricity. This is illustrated by their wattage (W). The higher the wattage of the item the more electricity it uses. For example, a hair dryer can be 1,200W (1.2kW) compared to a radio using 10W, meaning the hair dryer uses considerably more energy and thus costs more to run.

The difference in wattage between traditional and LED bulbs

The large variance between an LED bulb and, say, a halogen bulb wattage is the reason LEDs are so much cheaper to run. To show the comparison, we have a 5W LED GU10 that replace and produce the same light as a 50W halogen spotlight. This means that the LED spot uses 90% less electricity to run and therefore it costs 90%

We have 6W Led bulbs that are replacements for 60W halogen bulbs, again saving 90% energy and cost.

How much does one LED bulb cost to run?

As you can tell there are several factors that dictate the running cost of a single bulb, but all of them fit into the formula below:

cost of running led bulb formula

Now you can apply this to the bulbs in your home no matter if they are LED or not.

5W GU10 LED; (5/1000) x 1 x 14p = 0.07p per hour to run
50W GU10 halogen; (50/1000 x 1 x 14p = 0.7p per hour to run

Typical Home Example

Homes vary in size and preference of lighting but we will use the following in this instance:

Kitchen  9x 5W spotlights
Livingroom 4x 2W candle, 2x 6W B22 bulbs
Hall  2x 4W B22 Bulbs
Landing  1x 6W B22 Bulb
Bedroom 1 1x 6W B22 bulb, 1x 4W E27 bulb
Bedroom 2  2x 6W B22 bulbs
Bathroom 6x 5W spotlights

We will say this home has its lighting on an average of four hours a day.

Using our calculation this comes to:

(131W/1000) X 4 x 14p = 7.336p

To work out the yearly cost you simply multiply by 365 days = £26.78

We can do the same for halogen spotlights and bulbs in the same scenario:

Kitchen 9x 50W spot lights
Livingroom 4x 20W candle, 2x 60W B22 bulbs
Hall 2x 40W B22 Bulbs
Landing 1x 60W B22 Bulb
Bedroom 1 1x 60W B22 bulb, 1x 40W E27 bulb
Bedroom 2 2x 60W B22 bulbs
âBathroom 6x 50W spotlights

(1310W/1000) X 4 x 14p = 73.36p

The yearly cost in this instance would be £267.76

As you can see, the savings each year in this example would be £240.98.

This example is for a quite modest two bedroom home. If you have more rooms the cost and savings will go up dramatically. Also in the winter you could be using your lighting for much longer than four hours, again increasing the cost and potential savings.