Most people underbuy by about half, discover it on the ladder, and end up with two different bulb colors on the same roof. Ten minutes of measuring prevents it.
Step one: measure the roofline
Walk the perimeter of what you intend to light and measure along the ground beneath each run: eaves, gable rakes, porch edges, dormers. Add the runs together. Do not measure your whole perimeter unless you are lighting the whole perimeter.
Step two: bulbs per foot
C9 bulbs on standard 12-inch spacing means one bulb per foot. On 8-inch spacing, roughly 1.5 bulbs per foot, which reads noticeably bolder from the street and costs proportionally more.
| Roofline | At 12-inch spacing | At 8-inch spacing |
|---|---|---|
| Rambler front, 80 ft | about 80 bulbs | about 120 bulbs |
| Rambler full wrap, 160 ft | about 160 bulbs | about 240 bulbs |
| Two-story front, 140 ft | about 140 bulbs | about 210 bulbs |
| Two-story full, 300 ft | about 300 bulbs | about 450 bulbs |
Step three: add the extras
- Wrapping a tree trunk: roughly 100 bulbs per vertical foot of trunk at tight wrap, far less at loose spiral.
- Columns and posts: measure height, then double for a spiral wrap.
- Shrubs: plan by canopy width, not height.
- Ten percent spare. Always. You will need it.
Then check your power
Add up the wattage before you plug in. A 15-amp circuit gives you about 1,440 watts to work with at 80 percent load, and that includes anything else already on the circuit.
We size, power and test every install before we leave.
Book My InstallCaptain Clean Holiday Lights installs warm white C9 roofline lighting from Bellingham to Everett and across Whidbey Island. A seasonal service of Captain Clean Pro Wash, established 1985.
(360) 404-7167
