Solar Panel Tilt Angle Calculator

About this calculator

A fixed solar panel captures the most energy when it's aimed roughly perpendicular to the sun's rays at solar noon, and the ideal tilt angle for that depends on your latitude and which season you're optimizing for. The common rule of thumb is tilt ≈ latitude for a year-round balance, latitude + 15° for winter (when the sun sits lower in the sky), and latitude − 15° for summer (when the sun rides higher overhead).

A site at 40° latitude, for example, would use roughly a 40° tilt for annual output, 55° to favor winter production, or 25° to favor summer — the winter adjustment compensates for the sun's lower arc so panels still face it more directly.

Homeowners and installers use this to set a fixed-mount array's angle without a solar tracker, trading off summer versus winter yield depending on whether the goal is annual maximum output or covering heating-season loads.