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Sheet 13 · Lighting

How many fairy lights do I need for my tree?

The shops that sell lights have a rule, and they disagree with each other by a factor of two. Lights4fun says a hundred lights for every two feet of tree. John Lewis says a hundred for every foot, for ‘maximum impact’. Both are right; they are describing different trees. Six hundred lights on a six-foot tree is the one in the John Lewis photo, three hundred is the one in the Lights4fun photo, and the box of a hundred you bought last year is why last year’s tree looked like a lamppost in a hedge.

Put the height and the look in. The sheet gives you the number, rounds it up to the strings you can actually buy, tells you how much cable that is, and, if the tree is going in a window with no socket, how many AAs you will get through before Boxing Day.

1Work it out

The tree
How much light
Mains or battery
500lights

About 450 lights for a 6 ft tree at that look, so buy 500: 3 strings of 200, or one long string. That is roughly 25 m of lit cable, before the lead to the plug.

Get a 500-LED warm white string (fits a 5 ft tree at the usual look) on Amazon.co.ukor search Amazon.co.uk for “500 LED christmas tree lights warm white”

2Lights per foot

Both rules assume a normal tree, lit all the way round, with the lights wound in and out of the branches rather than draped round the outside. A slim tree takes fewer, a fat one more. The middle setting on the sheet splits the two rules, and it is the one most trees in most living rooms end up at. Lit length matters too: at Lights4fun’s five metres per hundred lights, a 1,000-light string is fifty metres of cable, which sounds absurd and is right, because you are wrapping a cone.

3One long string or several

One string of 1,000 is one plug, one run of cable and one transformer to hide. Several strings of 200 are more plugs, more joins, and more ways to have half the tree go out on Christmas Eve. Socket near the tree: one long string on a mains transformer. Lights going round a window or up a banister: shorter strings, or battery ones.

4Battery sets

A battery string takes three AAs, sometimes two, and a set of 100 LEDs runs a week of evenings on a fresh set before it dims. Timer sets (six hours on, eighteen off) make the batteries last a month, and if the lights are going somewhere you cannot reach a switch, the timer is the thing to buy, not the brightness. Rechargeables work, and they are the cheaper answer by the second week.

5Warm white, cool white, or the box of nine colours

Warm white is the yellow of an old bulb and the one that looks like Christmas. Cool white is bluer, brighter, and looks like a dental practice. Multicolour is for the children, and the children are right. There is no rule; there is only the picture in your head.

6Where to get it

Those links go to Amazon.co.uk and earn this site a commission if you buy. The price is the same either way, and nothing on this sheet changes because of it.

7Where the numbers come from

  1. How many lights for my Christmas tree?, Lights4fun. 100 bulbs or 5 metres of lights per 2 ft of tree; a 6 ft tree 300 bulbs or 15 metres (read 17 October 2026)
  2. How to decorate a Christmas tree, John Lewis. Use 100 lights per foot of tree; a 4 ft tree needs at least 400 for maximum impact (read 17 October 2026)
  3. How many lights do I need for my Christmas tree?, Festive Lights. Lengths by tree height: 4 ft about 5 m, 6 ft about 10 m, 7 ft about 20 m, 8 ft about 40 m (read 17 October 2026)
  4. This sheet’s own rules of thumb, stated where they are used, whichfits.uk (read 17 October 2026)

Data on this sheet last changed 17 October 2026.