Solar Panel Angle Calculator

A fixed panel gathers the most when it faces the sun squarely at solar noon, which sets the tilt at the gap between your latitude and the sun declination. Enter a latitude to get the year-round angle and the two solstice angles, or a date to get the angle for that one day. A third tab gives the minimum spacing between tilted rows so the front row does not shade the one behind it at midwinter. The declination comes from Cooper's equation, with the solstice swing taken as 23.45 degrees either side of the equator. Roof pitch, snow and shading usually decide the angle you can actually build long before the sun does.

Calculator Type

One latitude in, four tilts out: the year-round setting and the three seasonal ones a tilting mount would be moved between.

Positive north of the equator, negative south of it. Take it from a map or your phone; the longitude does not matter.
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The sun declination for a given day, and the tilt that is square to it at solar noon.

Negative south of the equator.
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How far apart tilted rows have to sit so the front row does not shade the one behind it at midwinter.

Measured along the tilt, in whatever unit you like. The spacing comes back in that same unit.
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