Christmas Lights Calculator

Tree lighting rules of thumb count mini lights per foot of height — sparse (~75/ft), classic (~100/ft), or dense (~150/ft). Dense coverage suits focal trees in picture windows; sparse works for secondary trees or when you mix garland and ornaments heavily.

Divide total bulbs by bulbs per strand (often 50, 100, or 300 on LED sets) to get strand count. Round up — partial strands still need a full set purchase, and extra length helps wrap inward branches.

Outline mode counts bulbs from run length and spacing — for example 4-inch spacing on a 40-foot roofline needs about 120 bulbs (40 ft × 12 in/ft ÷ 4 in). Match spacing to the light set you buy; C9 roof lines often use wider spacing than mini icicle sets.

Optional tree base diameter improves wrap-length estimates when you spiral from tip to base. Without it, the calculator still returns bulb and strand counts from height and density alone.

Watt estimates in results compare typical mini LED (~0.08 W per bulb) with incandescent mini (~7 W per bulb). Actual draw varies by bulb type, age, and manufacturer — use these figures for circuit planning, not utility bills.

Example: a 6 ft tree at classic density with 100 bulbs per strand needs about 600 bulbs and 6 strands. LED draw is roughly 48 W versus about 4,200 W for incandescent minis — a strong reason many households switch to LED.

Pair with the garland and ornament calculators for a full decorating shopping list. Never overload a single circuit — split outlets and use outdoor-rated cords for exterior runs.