Christmas Tree Lights Calculator
Find how many Christmas lights your tree needs from its height, shape and how bright you want it, in strings of 100 and total feet of lights.
Height is only part of it. A slim or pencil tree has less to wrap, and how bright you like it can halve or double the count. This works it out from all three and turns it into boxes of 100 lights to buy.
Your tree
Its height and how wide it is for that height.
Height
From the floor to the top of the tree, without the topper.
Shape
How bright
The usual rule is 100 lights for every foot of tree. Go lower for a subtle sparkle or double it for a showpiece.
Lights for your tree
About 700 lights
For a 7 ft full tree with a classic look
A standard box of mini lights holds 100 bulbs on about 33 ft of wire. Buy a spare string or two for any that burn out.
💡About this calculator▼
The usual answer is 100 lights for every foot of tree, so 700 for a 7-foot tree. That works for a full tree with a balanced look, but slim and pencil trees have less to wrap, and plenty of people want a softer sparkle or a tree that blazes.
This works it out from three things: the tree's height, its shape (full, slim or pencil) and how bright you want it. You get the number of lights, how many strings of 100 to buy, and the total length of lights, in case you're buying longer strings or a spool.
Checked against the tree makers. The counts match a tree maker's own published ranges for 6- to 9-foot trees, and the slim and pencil figures come from how many lights the factory puts on the same tree in each width.
Start with the height. The common rule from tree makers is 100 lights for every foot of tree for a balanced look. A soft glow uses about half that, and an extra-bright tree doubles it: a 7-foot full tree takes about 400, 700 or 1,400 lights (rounded up to whole strings of 100).
Then the shape. A narrower tree has less surface to wrap. One maker's 7½-foot tree comes with 750 lights in its full shape (59 inches wide), 600 as a slim tree (48 inches) and 350 as a pencil tree (32 inches). So slim trees here take four-fifths of the full count and pencil trees half.
Then round up to strings. Mini lights come in boxes of 100 bulbs on about 33 feet of wire, so the count rounds up to whole strings, and the total length is 33 feet a string.
Worked example. A 7½-foot slim tree with the classic look: 7.5 × 100 × 0.8 = 600 lights, 6 strings of 100, about 200 feet of lights.
📐How it's calculated▼
Lights = height (ft) × lights per foot × shape share, rounded up to the next 100.
Lights per foot: soft glow 50, classic 100, extra bright 200. Shape share: full 1, slim 0.8, pencil 0.5.
Strings = lights ÷ 100. Total length = strings × 33 ft.
7 ft full, classic: 700 lights, 7 strings, about 230 ft. 7 ft full, extra bright: 1,400 lights, 14 strings. 7½ ft pencil, classic: 375, rounded up to 400 lights in 4 strings, about 130 ft.
🔍Finding your inputs▼
Height: From the floor to the top of the tree, not counting the topper.
Shape: Full is the classic wide cone. Slim trees are about four-fifths as wide for their height, and pencil trees about half as wide. If you're not sure, the box or the tag at the lot usually says.
How bright: Classic is the usual 100 lights a foot. Soft glow is about half that, for a gentle sparkle that lets ornaments stand out; extra bright doubles it, for a tree that lights up the room.
⚠️Special situations▼
My lights come in strings of 50 or 300
Use the total length row, or divide the light count by the bulbs in your box: 700 lights is 14 strings of 50 or about 2½ strings of 300 (buy 3). Check that the bulb spacing is similar, about 4 inches, or the coverage will look different.
I have a pre-lit tree but want it brighter
Look up how many lights it came with, then compare with the count here. A 7-foot full tree with the classic look is about 700; if yours came with 500 and you want extra bright (about 1,400), add 9 strings of 100.
Are LED lights different?
Not for the count. A standard LED string of 100 runs about the same 33 feet as the old mini lights, so the same number of strings covers the tree. If you prefer a softer look, pick the soft glow card.
❓Common questions▼
How many lights do I need for a 7 ft Christmas tree?
About 700 for a full 7-foot tree with a classic look, which is 7 strings of 100. For a dramatic, extra-bright tree, about 1,400; for a soft glow, about 400. A slim 7-foot tree takes about 600 for the classic look, and a pencil tree about 400.
How many lights for a 6 ft Christmas tree?
About 600 for a full 6-foot tree with a classic look, up to 1,200 for an extra-bright one. That is 6 to 12 strings of 100. A slim 6-foot tree takes about 500 and a pencil tree about 300.
How many lights for a 9 ft Christmas tree?
About 900 for a full 9-foot tree with a classic look and up to 1,800 for extra bright, which is about 300 to 590 feet of lights. A slim 9-foot tree takes about 800.
How many strands of lights do I need for my tree?
For the classic look, one string of 100 for every foot of a full tree: 7 strings for a 7-foot tree. Slim trees take about four-fifths as many and pencil trees about half. Buy a spare string or two for any that burn out.
How many feet of lights do I need for a Christmas tree?
About 33 feet of lights for every 100 bulbs. A 7-foot full tree with the classic look takes about 230 feet; a 9-foot tree about 300 feet.