How Much Does It Cost to Run Christmas Lights? (UK, per Hour)
Very little, if they are LED. A 5 W set of LED tree lights on for 6 hours an evening uses 0.03 kWh, about 0.8p a night, and 29p from 1 December to Twelfth Night (36 nights) at 27p per kWh. A 40 W filament set costs 8 times as much. Check the power in watts on the label or the plug, then use the electricity cost calculator with your own unit rate.
Running costs by the power on the label
On for 6 hours a night for 36 nights (1 December to 5 January), at 27p per kWh. The descriptions are typical examples, not a rule: two sets that look alike can differ a lot, so read the label.
| Power | Typical lights | Per night | For the season | Energy for the season |
|---|---|---|---|---|
| 3 W | Small LED set, battery or plug-in | 0.5p | 17p | 0.6 kWh |
| 5 W | LED tree lights (a few hundred bulbs) | 0.8p | 29p | 1.1 kWh |
| 10 W | Large LED set or LED icicle lights | 1.6p | 58p | 2.2 kWh |
| 25 W | LED net or curtain lights, several sets | 4.1p | £1.46 | 5.4 kWh |
| 40 W | Older filament (incandescent) mini lights | 6.5p | £2.33 | 8.6 kWh |
| 100 W | Large filament set or an older outdoor display | 16p | £5.83 | 21.6 kWh |
| 200 W | Big outdoor display with figures | 32p | £11.66 | 43.2 kWh |
A whole house of lights
A tree, a window, the front of the house and one lit figure in the garden, all LED:
| Lights | Power | For the season |
|---|---|---|
| Tree lights (LED) | 5 W | 29p |
| Window lights (LED) | 3 W | 17p |
| Outdoor icicle lights (LED) | 10 W | 58p |
| Lit outdoor figure | 25 W | £1.46 |
Together that is 43 W, which costs about £2.51 for the season at 6 hours a night. Cutting it to 4 hours an evening with a plug-in timer brings it down to £1.67. The lights that cost most are the big ones: inflatable figures run a fan all the time, so check the label of anything that moves or blows up.
LED or filament, and leaving them on
- A 40 W filament set costs £2.33 for the season against 29p for a 5 W LED set. If your old lights still work the difference is small in money, but LED sets also run cooler, which matters on a real tree.
- Leaving LED tree lights on all day and night costs about £1.17 for the season instead of 29p. Many manufacturers advise switching decorative lights off when you go out or go to bed, so a timer is the better habit anyway.
- Outdoor lights must be sold for outdoor use. Use an outdoor-rated extension lead, keep connections off the ground and out of puddles, and plug them into a socket protected by an RCD.
If your unit rate is different
The unit rate is the price per kWh on your bill. It changes with the price cap and your tariff, so here are three rates for the same lights over the whole season:
| Unit rate | 5 W LED tree lights | 40 W filament set | The 43 W house above |
|---|---|---|---|
| 24p per kWh | 26p | £2.07 | £2.23 |
| 27p per kWh | 29p | £2.33 | £2.51 |
| 30p per kWh | 32p | £2.59 | £2.79 |
For heaters and other appliances, see how much it costs to run appliances and the running cost of a 2 kW heater. For the Christmas dinner itself, see Christmas dinner timings.
Frequently asked questions
How much does it cost to run Christmas lights per hour?
A 5 W LED set uses 0.005 kWh an hour, which is about 0.1p an hour at 27p per kWh. A 40 W filament set costs about 1.1p an hour.
Is it expensive to leave Christmas lights on all night?
Not for LED lights: a 5 W set on 24 hours a day costs about £1.17 from 1 December to Twelfth Night. It is still better to switch them off at night or use a timer, as many manufacturers advise.
How many watts do Christmas lights use?
LED sets are often between 2 and 10 W, and older filament sets 40 W and more. The power is printed on the label, the plug or the transformer.
How much do outdoor Christmas lights cost to run?
A 43 W display of LED lights and one lit figure costs about £2.51 for the season at 6 hours a night and 27p per kWh.
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