Solar Panel Tilt & Azimuth Calculator

For the best year-round production, tilt solar panels at roughly your latitude — panels at about 34° for Los Angeles, or 40° for New York. To favor winter output (common for backup and off-grid systems) add about 15°; to favor summer, subtract about 15°. The calculator applies these rules and keeps a 10° minimum so rain can wash the panels clean.

Towards the equator: true north in the southern hemisphere (azimuth 0°) and true south in the northern hemisphere (azimuth 180°). Note that is true, not magnetic — a compass reads several degrees off in many places, so correct for your local magnetic declination or use a satellite map to sight the roof.

Any maps app shows it — press and hold on your location and read the first coordinate. Ignore the minus sign or the N/S letter and enter the number, then pick your hemisphere. US city examples: Miami 26°N, Los Angeles 34°N, New York 41°N, Seattle 48°N.

Less than most people expect — output falls with the cosine of the error, so being 15° off the optimum typically costs only around 3–4%. Facing the wrong direction hurts more: an east- or west-facing roof gives up roughly 15–20% compared with facing the equator. That is why it rarely pays to fight your roof’s pitch, but orientation is worth getting right.

On a roof, almost never — the mounting cost and hassle outweigh the few percent gained. Adjustable ground or pole mounts can be worth changing twice a year (winter and summer settings) on off-grid systems where every winter kWh counts. Otherwise, set the year-round angle — or the winter angle if your critical loads are in winter — and leave it.

Use tilt frames at 10–15° minimum rather than laying panels flat: flat panels collect dirt and pond water, losing far more to soiling than the angle maths suggests. On flat roofs you can also face the frames anywhere, so point them at the equator — and space the rows so they don’t shade each other in winter, when the sun is low.