Christmas Lights Calculator
Strands of lights needed for a tree, house or roofline.
Enter your values
roofline, tree height x wraps, etc.
ⓘ Live results
Results
- Strands needed
- 4
- Total coverage length
- 88 ft
- Total light length bought
- 100 ft
Quick answer
Lights needed is the perimeter or height to be covered divided by the coverage per strand, rounded up.
strands = ceil(total length / length covered per strand)
How to use the Christmas Lights Calculator
- 1Measure the total length to cover — roofline perimeter, or tree height times number of wraps for a tree.
- 2Check the length covered by one strand of lights (commonly 25 or 50 ft).
- 3Add 10% extra for overlaps at corners and reaching outlets, then round up to full strands.
Inputs explained
- Total length to cover(ft)
- roofline, tree height x wraps, etc.
Worked example
Using the values the calculator loads with:
Inputs
- Total length to cover80 ft
- Length per strand25 ft
- Extra for overlap/outlets10 %
Results
- Strands needed4
- Total coverage length88 ft
- Total light length bought100 ft
Frequently asked questions
How many wraps does a tree need for a full look?
For a lush look, plan on roughly 1.5-2x the tree's height wrapped per foot of circumference — many use 100 lights per foot of tree height.
Should I buy the same brand/color for all strands?
Yes, mixing brands or bulb temperatures (warm vs cool white) can look inconsistent once lit at night.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.