Projection mapping distance
Estimate projector throw distance from throw ratio × image width — useful for Halloween house projections and yard screens.
distance_ft = throw_ratio × image_width_ft · width_ft = distance_ft ÷ throw_ratio
When to use
This tool helps when you want a projection mapping distance planning figure with the assumptions written down. You will enter throw ratio (distance ÷ width), image / façade width (feet), and projector distance (feet).
Estimate projector throw distance from throw ratio × image width — useful for Halloween house projections and yard screens. Keep units consistent (feet vs inches, watts vs amps), then use the formula box to see how each term contributes.
Stop and ask a licensed electrician when loads, hardwired outlets, or roof work go beyond temporary plug-in holiday displays.
Short-throw ~0.4–1.0; standard ~1.2–2.0 — check your lens/manual.
Worked example
Example inputs from the form defaults — Throw ratio (distance ÷ width) = 1.5; Image / façade width (feet) = 16; Projector distance (feet) = 24 — are plausible homeowner figures, not a survey of your roofline.
Compute with: distance_ft = throw_ratio × image_width_ft · width_ft = distance_ft ÷ throw_ratio. Show intermediates before the final count or cost.
When the calculator and scratch math disagree, fix units first; the projection mapping distance model is only as good as consistent inputs.
Limits / assumptions
Assumptions: inputs match the hints (measured eaves, nameplate watts, package strand length, and so on). Terms not named in the formula are not secretly included.
Limits: outdoor weather, GFCI trips, and real stock sizes vary. Prefer outdoor-rated cords and clips; ladder and roof work need their own safety practices.
Responsibility: confirm safety-critical electrical and height decisions with manuals and, when needed, a qualified professional. PWC Lights does not stamp displays.
FAQ
Where is throw ratio listed?
Projector/lens spec sheets: “throw ratio” or distance range for a given screen width.
House not flat?
Use the average width you want filled; mapping software handles warp.
Brightness?
This is geometry only — lumen needs depend on ambient light and surface color.
Spotlight wash instead?
See spotlight beam coverage for flood/spot diameter.