Do Christmas lights use a lot of electricity? Find out how much

In 1880 Thomas Edison, the inventor of the lightbulb, first hung a strand of electric lights around the outside of his laboratory; and in 1882 Edward Johnson who worked with Edison hand-wired a string of electric lights around a tree to replace the tradition of using candles. But, it took a further 40 or so years before people started to trust electricity enough to start decorating their homes and trees!

Nowadays, on average, homes have Christmas decorations up for 38 days and most sources suggest we keep our Christmas lights twinkling for around six hours a day! 

This blog looks at everything to do with Christmas lights! From how much electricity they use, to different types, tree size and average amount of lights, to the environmental impact we could cause through using them.

How much electricity do Christmas lights use? 

This depends on the actual type of Christmas lights, their electricity usage, and how long they're on for.  LED string lights are designed to be energy efficient, and comparatively cost a lot less that other household electricity users. 

Which? suggest that even over a generous Christmas period, for example 1 December to 31 January, using your Christmas lights for six hours a day, one string of LED lights will cost you about 44p.

Interestingly, the length of light chain doesn't make a huge difference to the running cost. For example,  a 400 bulb chain on for six hours a day, over 62 days, equates to roughly 47p on average. Whereas, a 200 LED bulb chain, for the same times, works out at 41p on average.

How many lights should you use for the size of your Christmas tree?

Apparently 1.5 foot of lights per foot of tree is the ideal ratio, or about 46cm per 30cm of Christmas tree. This Christmas tree calculator table will give you a quick guide to number of bulbs to tree height. Don't forget, if your tree is very full and round, you'll probably want more lights:

How to calculate energy usage from Christmas lights 

To work out the exact kilowatt per hour (kWh) of your lights, take the wattage of each string of lights (this should show on the box or packaging) and divide this number by 1000. For example, Christmas lights that use 40 watts of energy will equate to 0.04kWh. You can also use a Christmas light energy calculator tool to help work out your use costs.

• Power: 6 Watts = 0.006 kW
• Hours: 6 hours
• Cost per kWh: 26.35 pence (average Ofgem UK electricity price cap for Direct Debit customers, Oct-Dec 2025) 

According to Which? this is how LED lights compare to other household goods in terms of energy use and cost:

LED Christmas lights versus incandescent and fibre optic lights

Depending on the look you're going for, you can buy indoor LED lights, traditional incandescent fairy lights, lighted garlands, outdoor chain Christmas lights perfect for garden trees and bushes, plug-in stringed Christmas lights, battery powered ones and even solar-powered lights!  But for the average indoor home Christmas light, let's compare LED, incandescent and fibre optic bulbs:

Environmental impact of Christmas lights

How to lessen the environmental impact of Christmas lights

• Buy LED lights: This is probably one of the most effective changes you can make to your household's Christmas light's impact on the environment. LED lights use a lot less energy than traditional incandescent bulbs, and last much longer.
• Use timers or smart plugs: Schedule lights only turn on only when you want them to, for example between 5pm to 10pm. This means you know they're all switched off overnight or when you leave the house, helping you save energy, money and reduce light pollution.
• Solar-powered lights: If you're looking to buy new outdoor Christmas decorations, look out for ones that are powered by solar and help reduce the need for grid electricity.
• Reduce quantity: Consider using fewer lights or focusing them on specific features rather than illuminating the entire front of your home or wall. Some people aim lights downwards and use shields to help prevent light spill into the sky.
• Choose warmer colors: Warm-coloured lights (amber, red) are less harmful to wildlife than bright white or blue lights.
• Recycle old lights properly: To help improve the entire life-cycle of your lights, when they're no longer working and you're looking to throw them away, check your local council's website for specific small electrical household waste or recycling schemes.
• Buy high-quality, durable products: Investing in better quality lights may be initially slightly more expensive, but they should last for many more Christmases to come, which will help reduce manufacturing demand and waste.
• For more ideas, read our blog on ways to have an eco friendly Christmas for more ways to be sustainable during the festive season.

Top tips for saving electricity with Christmas lights

Do Christmas lights get hot and become a fire risk?

Christmas lights can get hot and become a fire risk, especially older or damaged incandescent bulbs and lights with faulty wiring. Try to only use certified lights, and remember to check them for damage, avoid overloading sockets, and always turn them off when you're going to bed or leaving your home. 

Do Christmas inflatables use a lot of electricity?

They're actually cheaper to run than you may think. An inflatable using 24 watts costs around 0.6p per hour. So, that’s just 5p for eight hours, which across December adds up to only about 18.6p!

Do solar Christmas lights work in the UK?

Yes, solar Christmas lights do work in the UK, but how brightly they shine will depend on the quality of the lights and where you place them. High-quality, hybrid solar/USB lights are made for our long, dark nights and give reliable performance. Try positioning the solar panel in a location with as much direct sunlight as possible and consider hybrid USB charging models for more consistent power. 

Do Christmas lights make your electricity bill high?

Depending on how you choose to use your lights, the type of light and how long they're on for will all make a difference to  how much you spend on your electricity bill at Christmas time. But, the average LED fairy lights on a tree really do cost a surprisingly little amount compared to many of the other appliances we use in our homes. However, it's really important your household is on the best gas and electricity deal for your energy needs; if you need help better understanding energy, try to compare energy tariffs, consider whether a standard variable rate tariff or a fixed energy tariff works better for your home. You may need to change energy tariff or switch energy supplier. 

Looking ahead

We want energy to work for you – for the long-term. We’re giving away free electricity our customers can use every Sunday with our Sunday Saver challenges, making energy easier to understand, offering energy tariffs that use electricity when its cheapest, installing smart meters so customers can get our cheapest deals and best offers, and using Which? trusted installers for our low-carbon products. And with our ongoing improvements in customer service and commitment to helping build Britain’s zero-carbon future, we’re here to support you—not just today, but for years to come.