Solar Panel Angle Calculator Formula

Understand the math behind the solar panel angle calculator. Each variable explained with a worked example.

Use the Solar Panel Angle Calculator

Formulas Used

Optimal Annual Tilt

optimal_tilt = latitude * 0.87 + 3.1

Winter Tilt (steeper)

winter_tilt = latitude * 0.87 + 3.1 + 15

Summer Tilt (flatter)

summer_tilt = abs(latitude * 0.87 + 3.1 - 15)

Adjusted Tilt

adjusted_tilt = latitude * 0.87 + 3.1 + season_adjustment

Variables

VariableDescriptionDefault
latitudeLatitude(°N)40
season_adjustmentSeason Adjustment(°)0

How It Works

Optimal Solar Panel Tilt Angle

The ideal tilt angle for solar panels depends primarily on latitude. Panels should face the equator (south in the Northern Hemisphere) at a tilt that maximizes annual energy capture.

Formula

Optimal Tilt = Latitude x 0.87 + 3.1°

This regression approximation works well for latitudes between 25° and 55°. Steepen by 15° in winter and flatten by 15° in summer for seasonal optimization. Adjustable mounts that change tilt seasonally can gain 5-10% more annual energy.

Worked Example

Solar panels at 40°N latitude.

latitude = 40season_adjustment = 0
  1. 01Optimal annual tilt = 40 x 0.87 + 3.1 = 37.9°
  2. 02Winter tilt = 37.9 + 15 = 52.9°
  3. 03Summer tilt = 37.9 - 15 = 22.9°

Ready to run the numbers?

Open Solar Panel Angle Calculator