Solar Panel Angle Calculator

Because a panel tilted to match latitude points, on average across a full year, most directly at the sun's position as it moves through the sky between summer and winter extremes. It is a starting-point rule of thumb in solar design, not a precisely optimized angle for any single day -- fine-tuning for a specific month or goal (like winter heating load) shifts the ideal angle away from this baseline.

The sun sits lower in the sky during winter months, so a steeper panel angle is needed to catch sunlight more directly as it arrives at a lower angle above the horizon. In summer the sun sits higher overhead, so a shallower tilt captures more of that more-overhead light without needing as much of an angle.

Yes -- panels should face toward the equator to track the sun's higher midday position, which means true south for northern-hemisphere sites and true north for southern-hemisphere sites. This calculator flips the recommended azimuth automatically based on whether the entered latitude is positive or negative.

This calculator estimates it using the cosine of the recommended tilt angle as a simplified proxy for how directly sunlight strikes the panel -- the steeper the optimal tilt at a given latitude, the more a flat panel underperforms relative to that optimal angle, since a flat panel receives sunlight at a less direct angle than one tilted toward the sun's average path.

Annual Average Tilt always equals the absolute value of latitude, no matter which season is selected -- it's a season-independent reference baseline. Optimal Tilt, by contrast, applies the seasonal adjustment on top of that baseline, so the two outputs diverge whenever a specific season (rather than "Annual Average") is chosen, and match exactly when it is.