How Many Solar Panels Can You Fit on Your Roof?

Solar Panel Roof Fit Calculator

Most roofs only have about 75% usable space after accounting for vents, pipes, chimneys, dormers, spacing rules, and required fire setbacks.

This calculator automatically applies that factor so your results reflect real-world install conditions.

Roof Shape: Rectangle Square Units: Feet (ft) Inches (in) Centimeters (cm) Length: Width: Panel Wattage (Dimensions): 200W — 4.5 ft × 3 ft 300W — 6 ft × 3 ft 400W — 5.6 ft × 3.7 ft 500W — 6.7 ft × 3.5 ft Calculate