Outdoor comfort planning
Pergola Shade Planner
Estimate slat count and direct-sun shade coverage from pergola dimensions, slat spacing, and sun angle.
Your estimate will appear here
Enter your project details and calculate for a practical planning estimate.
How this estimate works
- • Slat count divides the pergola span by slat face width plus clear gap and rounds up.
- • Overhead coverage is slat face width divided by pitch. Slat-depth shadow is depth ÷ tan(sun altitude), projected by the angle across the slats.
- • Total direct shade is capped at 100%; target-gap guidance solves the same simplified shadow ratio for the requested percentage.
Before you begin
- • This is a simplified direct-shadow geometry model, not a structural design or full solar simulation.
- • It excludes latitude, date, clock time, roof height, tilted slats, surrounding buildings, trees, diffuse sky light, and reflected heat.
- • Slat spans, wind and snow loads, connections, footings, permits, and allowable lumber dimensions require qualified local design.
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