How many lights does a Christmas tree need?
Quick answer: A widely used rule of thumb is about 100 LEDs for every foot of tree height, so a 6 ft tree needs around 600 lights for a classic, evenly lit look. Use about 50 per foot for a light look and 150 per foot for a very full one.
Last updated: 12 November 2026
Too few lights and a tree looks patchy; too many and the cable is hard to hide. The answer depends on the height of the tree, how full its shape is and the look you like. This guide gives a rule of thumb for three densities, explains why bulb count and cable length are different things, and describes three ways of putting the lights on.
The rule of thumb
The most commonly quoted guide is 100 lights per foot of tree. It is a decorator's rule of thumb and not a standard, and some guides suggest more for a fuller look. We use three levels:
- Light: about 50 LEDs per foot. A simple, airy look that lets the branches and decorations show.
- Classic: about 100 LEDs per foot. Evenly lit from every side; the usual choice.
- Full: about 150 LEDs per foot. Generous sparkle, with light deep inside the tree as well as at the tips.
Lights by tree height
| Tree height | Light | Classic | Full |
|---|---|---|---|
| 4 ft (122 cm) | 200 | 400 | 600 |
| 5 ft (152 cm) | 250 | 500 | 750 |
| 6 ft (183 cm) | 300 | 600 | 900 |
| 7 ft (213 cm) | 350 | 700 | 1,050 |
| 8 ft (244 cm) | 400 | 800 | 1,200 |
| 9 ft (274 cm) | 450 | 900 | 1,350 |
| 10 ft (305 cm) | 500 | 1,000 | 1,500 |
Number of LEDs. These are rules of thumb for a full-shaped tree: a slim tree needs fewer, and a very wide or bushy tree needs more.
Our Christmas tree calculator works out the same figures for any height, together with baubles, tinsel and the size of tree skirt.
Bulb count or cable length?
Lights are sold by the number of LEDs, but what you wind round the tree is cable, so look at both. The lit length is the distance from the first bulb to the last. It depends on the spacing: 600 LEDs spaced 10 cm apart make about 60 m of lit cable, while the same number at 5 cm apart make about 30 m and look denser. Two sets with the same bulb count can therefore cover a tree very differently.
The lead is the unlit cable between the plug and the first bulb. A long lead is useful if the socket is not right behind the tree. Both figures are given on the product pages in our Christmas Lights department.
Cluster lights pack many LEDs onto a short cable, so their bulb counts are much higher for the same coverage. For cluster sets, go by the lit length and the height of tree the product page recommends, not by the table above.
Three ways to put lights on a tree
Whichever you choose, start at the plug end, at the bottom of the tree nearest the socket, and put the lights on before any baubles or tinsel.
- Round and round. Wind the lights in a spiral from the bottom to the top, keeping the gaps between the turns even. It is the quickest method and suits lights with wider spacing.
- Up and down. Divide the tree into three or four vertical sections and run the lights up and down each one in a zigzag. The cable never goes all the way round, so the lights lift off easily in January.
- In and out. Work along each branch from the trunk to the tip and back again. It takes the longest and uses the most lights, but it puts light inside the tree as well as on the surface, which gives the greatest depth.
Step back every few minutes and look at the tree through half-closed eyes; dark patches show up straight away. It is far easier to adjust the lights now than after the decorations are on.
Warm white, cool white or colours
This is a matter of taste, not a rule. Warm white has a soft, candle-like glow that sits well with traditional reds, greens and golds. Cool white is crisper and suits silver, blue and frosted schemes. Multicoloured lights look bright and playful. Many sets have a controller with several modes, such as steady, twinkle and slow fade, so one set can do more than one job. If you are adding to lights you already own, match the colour description carefully, because "warm white" from two different makers can look slightly different side by side.
Why LED
Electrical Safety First notes that LED Christmas lights can use 80–90% less electricity than filament lamps, and that they use much less power and generate less heat. London Fire Brigade recommends LED lights for the tree for the same reason: the bulbs stay cooler. Most LED sets run at extra-low voltage through a transformer or from batteries or USB; the power type is on each product page.
Pre-lit trees and outdoor trees
A pre-lit tree already has its lights fitted, so there is nothing to count; you can still add a second set if you want a fuller look. They are in our Christmas Trees department.
A tree in the garden or on the porch is a different matter. Lights used outside must be made for outdoor use, and the 100-per-foot rule matters less than choosing a set with the right rating and enough lead to reach a protected socket. Our guide to Christmas lights safety in the UK explains the ratings, and suitable sets are in Outdoor Christmas Decorations.
Before you switch on
- Check the lights before they go on the tree. Electrical Safety First advises making sure they are not damaged or broken and that there are no loose wires.
- Do not overload the socket, and avoid relying on extension leads and adaptors where you can.
- Switch the lights off and unplug them before you go to bed or go out. London Fire Brigade suggests a timer if you think you might forget.
- Keep the lights away from paper and fabric decorations that could scorch.
Not sure which set to choose? Our FAQ covers power types and outdoor use, and you can ask us by email through the Contact us page.