How Many Christmas Lights Do You Need? Tree and Roofline Guide
Quick answer: a common rule of thumb is 100 mini lights per foot of tree height for a standard look, 150 for a full look and 200 for extra sparkle. A 6-foot tree needs about 600 to 1,200 lights, which is six to twelve strands of 100. For a roofline, divide the length in inches by the bulb spacing.
Too few lights look patchy and too many are expensive and hard to untangle. Use the simple numbers below, or the free Christmas lights calculator, to work out how many strands to buy.
Lights for a Christmas tree
Multiply the tree height in feet by the number of lights per foot you want.
| Tree height | Standard (100 per ft) | Full (150 per ft) | Extra sparkly (200 per ft) |
|---|---|---|---|
| 4 ft | 400 | 600 | 800 |
| 6 ft | 600 | 900 | 1,200 |
| 7.5 ft | 750 | 1,125 | 1,500 |
| 9 ft | 900 | 1,350 | 1,800 |
Divide the total by the number of lights on each strand. For a 6-foot tree with a full look, 900 lights is nine strands of 100. Treat the numbers as a starting point. Slim trees need less and wide trees need more.
Lights for a roofline, window or railing
Lights on a straight run are counted by length. Number of bulbs = length in inches ÷ spacing between bulbs.
| Run length | Larger bulbs, 12 in apart | Standard, 6 in apart | Mini lights, 4 in apart |
|---|---|---|---|
| 10 ft | 10 | 20 | 30 |
| 20 ft | 20 | 40 | 60 |
| 40 ft | 40 | 80 | 120 |
Check the product label for the spacing, since it varies from one set to another.
Safety checks before you plug in
- Look at the label for the maximum number of strands you can connect end to end. Never exceed it.
- Use lights rated for outdoor use outside, and keep plugs off the ground and out of puddles.
- Check each strand for frayed wires, cracked sockets and missing bulbs before you put it up.
- Switch lights off when you go to bed or leave the house. A timer makes this easy.
- Keep lights away from heat sources, and keep real trees watered.
Tips for a better-looking tree
- Test every strand before you start.
- Start at the base and wind upward, or work in sections from the trunk outward.
- Push some lights deeper into the branches for depth, and leave others on the tips for sparkle.
- Use one colour temperature, such as all warm white, so the tree looks even.
- Pick the tree first. See our tree size guide.
FAQs
How many lights do I need for a 6 foot tree?
About 600 for a standard look, 900 for a full look and 1,200 for extra sparkle. That is six, nine or twelve strands of 100.
How many strands of lights can I connect together?
It depends on the strand. The maximum is printed on the label or the plug. LED strands usually allow more to be connected than older incandescent ones, but always follow the label.
How many lights do I need for a roofline?
Divide the length in inches by the bulb spacing. A 40-foot roofline with bulbs 12 inches apart needs about 40 bulbs.
Are LED Christmas lights better?
LEDs use less electricity and run cooler, and you can usually connect more strands together. Check the label for the exact limits.
Should I put lights on before decorating?
Yes. Lights go on first, then garland and ornaments, so the wires are hidden behind the decorations.
Key Takeaways
- Rule of thumb: 100 to 200 lights per foot of tree height.
- For straight runs: length in inches divided by bulb spacing.
- Always follow the strand limit on the label.
- Use the free calculator to get a quick estimate.
More Christmas ideas
Free tools to try: