Solar Panel Tilt Angle Calculator (Optimal PV Array Angle)

The tilt angle of a fixed solar array sets how much of the year the panels face the sun squarely. This calculator gives the optimal year-round tilt from your latitude, along with summer and winter angles and the direction the array should face.

A fixed tilt roughly equal to the site latitude maximises annual energy; a slightly shallower angle (the Landau optimum) squeezes out a little more over the year. Steepening the panels in winter and flattening them in summer follows the sun’s changing elevation and is worthwhile for seasonally-adjustable mounts. Panels should face the equator — due south in the northern hemisphere, due north in the southern.

At latitude 28.6° (Delhi) the optimal year-round tilt is about 24.8° facing due south; drop to ~13.6° in summer and raise to ~43.6° in winter to follow the sun.

How the Solar Panel Tilt Angle Calculator Works

Enter your latitude and the calculator returns the year-round optimal tilt using the Landau relationship, plus the summer and winter angles (latitude ∓ 15°) for seasonally-adjustable mounts, and the direction the array should face based on your hemisphere. All angles are measured from horizontal.

Design Notes

• Fixed rooftop arrays: use the year-round optimal angle, or match the roof pitch if it is close.
• Ground mounts you can adjust: change tilt two to four times a year toward the seasonal angles.
• Very high latitudes: cap winter tilt near 60–70° to limit wind load and self-shading.