Solar Panel Angle Calculator
The tilt for fixed solar panels from your latitude, year-round and for each season, and the direction to face them.
Result…
How it's calculated
Year-round tilt = |latitude| Winter tilt = |latitude| + 15° (at most 90°) · Summer tilt = |latitude| − 15° (at least 0°) Face south in the northern hemisphere, north in the southern
The tilt is the angle between the panel and the ground: 0° is flat and 90° is upright. This uses a common rule of thumb. For a fixed panel all year, tilt it at your latitude: at the spring and autumn equinoxes the noon sun stands 90° minus your latitude above the horizon, so a panel tilted at your latitude faces it square on. The sun climbs about 23.4° higher by midsummer and drops as far by midwinter, so for panels you adjust by season the rule adds 15° in winter and takes 15° off in summer. Panels face the equator: south in the northern hemisphere and north in the southern. Use true (geographic) north or south, not the compass reading.
Your numbers, step by step
About the Solar Panel Angle calculator
This solar panel angle calculator gives the tilt for fixed solar panels from your latitude, plus seasonal tilts if your mounting can be adjusted, and the direction the panels should face. Enter your latitude as a positive number north of the equator or a negative number south of it, and it returns a year-round tilt, a winter, a spring and autumn and a summer tilt, and the height of the noon sun at the equinoxes. It uses a common rule of thumb rather than a weather model: tilt at your latitude all year, add 15° in winter and take 15° off in summer. Panels face the equator, so south in the northern hemisphere and north in the southern. The steps show why the rule works with your own latitude. To size the system itself, use the solar panel calculator.
How to use it
- Find your latitude in a map app; north of the equator is positive, south is negative.
- Type it into “Latitude”, for example 51.5 or −33.9.
- Read the “Year-round tilt” for a fixed mount and the direction under “Face the panels”.
- If you can adjust the mount, use the “Winter tilt”, “Spring and autumn tilt” and “Summer tilt” for each season.
Worked example
At latitude 51.5° north, the year-round tilt is 51.5° from horizontal, facing true south. At the equinoxes the noon sun is 90° − 51.5° = 38.5° above the horizon, so a panel tilted 51.5° faces it square on. The winter tilt is 51.5° + 15° = 66.5° and the summer tilt is 51.5° − 15° = 36.5°. At 33.9° south the panels face true north, with a year-round tilt of 33.9°, a winter tilt of 48.9° and a summer tilt of 18.9°.
Updated
Questions people ask
What angle should solar panels be at?
A common rule of thumb for fixed panels is a tilt equal to your latitude, measured from horizontal. It is a simple starting point; your installer may choose a different angle for your roof, weather or shade.
Which direction should solar panels face?
Towards the equator: south in the northern hemisphere and north in the southern hemisphere. Use true (geographic) south or north, not the compass reading, which differs by the local magnetic declination.
Why is the winter angle steeper?
The sun is lower in the sky in winter, so tilting the panels more steeply points them closer to it. In summer the sun is high, so a flatter panel faces it better.
What if my roof is at a different angle?
Most roof panels are fitted flush to the roof, so the roof pitch sets the tilt. A tilt that differs from the rule still produces power, just somewhat less; the roof pitch calculator converts a pitch into degrees.
What does the calculator not take into account?
Local weather, shade, snow, and whether you use more power in winter or summer. It gives a geometric rule of thumb, not the angle a solar design tool would find for your exact site.