How many light strings do I need to wrap my tree?

November 29, 2021

We’ve all seen tree trunks wrapped for Christmas, for weddings, and events. They are truly glorious. LED light strings with specifications allowing 100’s of feet of light to be run on a single outlet has revolutionized the density and number of lights that can be installed.

But how many light strings will I really need?

We have tried to create a formula, called in programmers, used graduate-level mathematic skills. Ultimately, we found that this question can be best answered with a piece of rope, a measuring tape, and a tree. As an alternative, use a string of lights that you have handy.

The reason, we’re going old school on this approximation is taste and style. Qualities that no super-computer can define.

Some folks choose to wrap tight. Some wrap loosely.

Only you know what kind of wrapper you are.

Quick way to calculate how many feet of lights needed to wrap a tree trunk

Here is our setup:

We are using a tree that has roughly an 18-inch diameter. We won’t need to use that number for any calculations but thought it might be good for reference. It is a pretty reasonably sized sample tree. Not too small. Not too big.

An 18-inch across pecan tree

Step 1. Mark off 12 inches on the tree trunk in question with the painters tape. (Chalk would be equally useful.)

12 inches between the tape

Step 2. Make a mark on the tape with the sharpie at the same places on the top and bottom tape. David thought this was unnecessary but I think it’s nice to easily see the beginning and end of the spiral.

The well discussed mark. Made with a sharpie.

Step 3. Use the cord to wrap the tree with the rope in the same way you’d wrap a set of lights adjusting the spiral to reflect how much light you want to see on the tree.

David winding the cord around the tree….

This wrapping resulted in 6 inches of distance between the spirals. This spacing is a good choice for larger trees.

An estimated 6 inches between the spirals in the lights

Step 4. After winding the cord at a 6 inch spiral between the tape spaced 12 inches apart, we marked the cord with tape and measured the total length of cord used.


The length of the cord for a 6-inch spaced spiral is 11 feet!

We decided to wrap the tree again but spaced the spirals 4 inches apart. This distance is commonly used in commercial applicaitons where intense lighting is the goal.

Here is what that looked like:

We measured again. The length of the cord this time was 23 feet.

Once the distance required to light a foot of the tree trunk is measured, just multiply that number in feet by the height of the tree trunk.

In our examples, let’s see how many feet of lights are needed to light 10 feet of tree trunk.

For roughly 6 inches between spirals

11 feet of lights x 10 feet of tree = 110 feet of lights which is 6 – 7 strings of LED lights spaced 4 inches apart

This installation can be lit with either glass or LED as long as any circuit does not exceed 210 watts.

For roughly 4 inches between spirals

28 feet of lights x 10 feet of tree = 280 feet of lights which is about 17 strings of LED lights

This installation could be glass with a splitter installed after the first 10 sets with 10 sets running in series and 7 sets running in series from the other side of the splitter. Seventeen LED strings could be run in series without splitters.

Guidelines for choosing lights

Choose the right spacing based on size of tree, desired look, available power, and budget.

  1. Common spacing for glass mini lights strings are 2.5, 4, and 6 inches. LED Mini lights are spaced 4 and 6 inches apart.
  2. Glass mini lights cannot be run more than 500 bulbs in series before a splitter is instroduced into the installation
  3. LED light strings can be connected 100’s of feet in series. Check the specification of the light strings for maximum number of strings that can be installed end to end.
  4. Use the total length of the light strings including the “head” and “tail” which is the measure of wire between the plug and first bulb.
  5. Add 10% or at least an extra string of lights to projects to account for irregularities in the tree trunk.
  6. The greater the distance between bulbs, the more economical the installation. More wire per light, is a good choice for larger trees. A smaller distance between bulbs can be a good choice for smaller tree trunks on smaller trees.

Ultimately, choice will be determined by:

  1. Budget
  2. Taste
  3. Electrical supply
  4. Size of trees and trunks

We’ve put this post together pretty quickly at the height of the Christmas season. We’ve made it simple and hope it is a good place to start.

More tips coming soon!

Look for more photos to come showing trees wrapped with different styles of lights, different bulbs spacings, and different trees.

While we can’t define how many lights you’ll need exactly with a computer program, the number can be tailored to every tree and every taste.

Shellie Gardner
Aside from throwing dinner parties that feature at least two kinds of cheese dip, Shellie's passions include travel, Mid-Century Modern furnishings and finding the perfect street taco. Has been known to snort laugh champagne.

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