Christmas tree lights calculator
Enter your tree’s height to see how many lights and strings to buy. The usual decorating rule is about 100 mini lights per foot of tree — more for a bright, full look.
Enter your measurements
- Strings to buy
- 7 strings
- Separate runs to plug in
- check the maximum on the box — LED strings can usually connect more
- Lights per foot of height
- 100
7 ft × 100 per foot = 700 lights
700 lights ÷ 100 per string = 7 strings
- LED sets list how many can be connected end to end on the box or tag. Stay under that number, and under three sets per extension cord (CPSC).
- Use lights with a UL, CSA or ETL label, check every string for broken sockets or frayed wire before it goes on, and never put electric lights on a metallic tree (CPSC).
Quick answers for common sizes
| Example | Answer |
|---|---|
| How many lights for a 6 ft tree | 600 lights |
| How many lights for a 7 ft tree | 700 lights |
| How many lights for a 9 ft tree | 900 lights |
Lights for a tree by height (style and shape as above)
| Tree height | Lights | Strings to buy |
|---|---|---|
| 3 ft | 300 lights | 3 strings |
| 4 ft | 400 lights | 4 strings |
| 5 ft | 500 lights | 5 strings |
| 6 ft | 600 lights | 6 strings |
| 6.5 ft | 650 lights | 7 strings |
| 7 ft | 700 lights | 7 strings |
| 7.5 ft | 750 lights | 8 strings |
| 8 ft | 800 lights | 8 strings |
| 9 ft | 900 lights | 9 strings |
| 10 ft | 1,000 lights | 10 strings |
| 12 ft | 1,200 lights | 12 strings |
There is no official standard for how many lights a Christmas tree should have — it is a matter of taste. The rule of thumb repeated by lighting retailers is about 100 mini lights per foot of tree height, and many people go to 150 or 200 for a tree that glows. This calculator uses that rule, adjusts it for a slim or full tree, and counts the strings.
Lights by tree height
| Tree | Subtle (50/ft) | Classic (100/ft) | Bright (150/ft) | Strings of 100 (classic) |
|---|---|---|---|---|
| 4 ft | 200 | 400 | 600 | 4 |
| 5 ft | 250 | 500 | 750 | 5 |
| 6 ft | 300 | 600 | 900 | 6 |
| 6.5 ft | 325 | 650 | 975 | 7 |
| 7 ft | 350 | 700 | 1,050 | 7 |
| 7.5 ft | 375 | 750 | 1,125 | 8 |
| 8 ft | 400 | 800 | 1,200 | 8 |
| 9 ft | 450 | 900 | 1,350 | 9 |
| 10 ft | 500 | 1,000 | 1,500 | 10 |
lights = height (ft) × lights per foot × shape (slim ¾ · standard 1 · full 1¼) big C7/C9 bulbs: half as many · strings = lights ÷ lights per string
Worked examples
- How many lights for a 6 ft tree — the apartment and living-room size.
- How many lights for a 7 ft tree — the height for an 8 ft ceiling, slim and full.
- How many lights for a 9 ft tree — tall ceilings, and how to keep the strings safe.
Connecting strings safely
The U.S. Consumer Product Safety Commission and the Electrical Safety Foundation give the same rule for incandescent lights: never connect more than three strings end to end. CPSC also advises no more than three standard-size sets on one extension cord. LED strings draw much less power, so manufacturers usually allow more to be connected — the maximum is printed on the box or the tag near the plug, and that number is the limit.
- Use tested lights. Look for a UL, CSA or ETL label (CPSC, ESFI).
- Inspect before hanging. Throw away strings with cracked sockets, bare wire or loose connections.
- Indoor lights indoors. Outdoor trees and porches need lights rated for outdoor use, plugged into a GFCI outlet.
- No lights on a metal tree (CPSC) — a damaged string can make the whole tree live.
- Water a real tree daily. A dry tree burns fast; keep it away from heaters and turn the lights off when you go out or to bed.
Wrapping tips
Wrap each branch from trunk to tip and back for a deep glow, or spiral around the outside for speed — the deep method uses more lights. Start at the bottom near the outlet so each string plugs into the one below. For the yard and patio, see the string lights calculator.
What you’ll need
- LED mini lights (100-light strings)Budget price
LED mini lights run cool and draw a fraction of the power of incandescent strings, so more strings can be connected end to end — follow the limit on the box.
See options on Amazon (opens in a new tab) - Outdoor plug-in timerBudget price
Turns tree and patio lights on at dusk and off at bedtime, so nobody leaves them on all night.
See options on Amazon (opens in a new tab) - Outdoor extension cordBudget price
Rated for outdoor use, long enough to reach the outlet without joining several cords. Plug outdoor lights into a GFCI-protected outlet.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How many lights per foot of Christmas tree?
About 100 mini lights per foot of height is the usual decorating rule, 150 to 200 for a very bright tree. It is a matter of taste, not a standard — slim trees need fewer, full trees more.
How many strings of lights can I connect together?
For incandescent lights, no more than three, according to CPSC and ESFI. LED sets usually allow more; the maximum is printed on the box or tag. CPSC also advises no more than three standard-size sets per extension cord.
How many lights does a 7½ foot tree need?
About 750 mini lights at 100 per foot — eight strings of 100. For a bright tree, about 1,100 to 1,500.
Are LED Christmas lights safer than incandescent?
LEDs run much cooler and use less power, which is why more of them can usually be connected end to end. Either way, use lights with a testing-lab label and follow the limits printed on the box.
Sources
- U.S. Consumer Product Safety Commission — Holiday decorating safety (CPSC 611) (opens in a new tab) — Use lights tested by an independent laboratory; no more than three standard-size sets of lights per extension cord; never put electric lights on a metallic tree.
- U.S. CPSC — Happy holidays start with safety (2025 news release) (opens in a new tab) — Never string together more than three sets of incandescent lights, and never overload outlets.
- Electrical Safety Foundation International — Top 10 holiday safety tips (opens in a new tab) — Never connect more than three strings of incandescent lights; look for UL, CSA or ETL certification labels.