LED curtain width panel count
Count how many pre-made LED curtain-light panels you need to cover a window or porch width for Prince William County Christmas façades.
panels = ceil(opening_width_in ÷ panel_width_in)
When to use
Use this for store-bought curtain / waterfall light panels (fixed width × drop), not for counting individual vertical drops.
Measure the clear width you want glowing. Round up so the last panel overlaps slightly rather than leaving a dark gap.
Pairs with the curtain-light drop-count tool when you are building a DIY strand curtain instead of buying panels.
Window, garage door section, or porch bay width.
Rated width of one curtain-light panel.
Optional side overlap so seams do not show dark.
Backup for a second window.
Worked example
Example defaults — Opening 72 in; Panel 36 in; Overlap 3 in; Spare 0.
With overlap, panels = ceil((opening − overlap) ÷ (panel − overlap)).
Compute: ceil((72 − 3) ÷ (36 − 3)) = ceil(69 ÷ 33) = ceil(2.09) = 3 panels.
Second example: one input changed
From the defaults (Opening width (inches) = 72; Panel width (inches) = 36; Overlap per joint (inches) = 3; Spare panels = 0), the calculator shows:
Panels needed: 3
Buy with spares: 3
Approx covered width: 102 in.
Now raise Opening width (inches) from 72 to 108 and keep the other entries. The result becomes:
Panels needed: 4
Buy with spares: 4
Approx covered width: 135 in.
Comparing the two runs tells you how sensitive the answer is to that one measurement. If a small change in it swings the result a lot, measure it twice.
Limits / assumptions
Units: widths in inches.
Assumptions: panels hang side-by-side; same drop length; overlap only at vertical joints.
Not a substitute: end-to-end plug limits or amp budgets for the whole curtain wall.
Confirm indoor/outdoor rating. Do not nail through wires. Keep curtains clear of open flames and hot bulbs on nearby garland.
FAQ
DIY strand curtain?
Use curtain light drop count for drops-per-foot math.
Odd window with trim?
Measure glass opening or trim-to-trim — be consistent.
Two stories?
Count panels per floor width; drops are a separate product length choice.
Voltage drop on long daisy chains?
Follow the set’s max connect rating; feed from both ends if needed.