Solar Panel Tilt Calculator
Enter your latitude to get the optimal tilt for year-round, winter-biased or summer-biased mounting, with the correct azimuth direction.
Open calculatorLast updated: 2026-09-15
How the calculation works
- The annual optimum roughly equals latitude — the panel normal then bisects the sun's seasonal arc.
- Winter optimization tilts steeper (low winter sun); summer optimization flatter (high sun).
- Azimuth: due south in the northern hemisphere, due north in the southern.
Worked example
Interpreting the result
Tilt matters less than people expect: within ±10° of optimum, annual yield changes only 1–3%. Orientation (azimuth) and shading matter far more. Steeper tilts shed snow and self-clean better with rain; flatter tilts integrate with roofs and reduce wind loading. Adjustable racks gain a few percent by tracking seasons.
Assumptions
- Clear-sky geometry; local cloud patterns can shift the optimum a few degrees.
- Fixed-tilt mounting (not tracking).
Limitations
- Rooftop constraints usually dictate tilt — the optimum is academic when the rack follows the roof plane.
- Single-axis trackers follow a different optimization entirely.
Suggested panel tilt (degrees) by latitude and season
| Latitude | Year-round | Winter | Summer |
|---|---|---|---|
| 10° | 10 | 25 | 0 |
| 20° | 20 | 35 | 5 |
| 30° | 30 | 45 | 15 |
| 40° | 40 | 55 | 25 |
| 50° | 50 | 65 | 35 |
| 60° | 60 | 75 | 45 |
Common rules of thumb: about the latitude for year-round output, steeper for winter and shallower for summer.
Worked scenario: latitude 40° in winter
For a site at 40° latitude the calculator suggests 55° in winter, when the sun is low, and the panels should face 180° (true south). A steeper tilt also helps snow slide off.
Mistakes to avoid
- Facing the wrong way. Panels face the equator: south in the northern hemisphere, north in the southern.
- Chasing the perfect angle on a roof. A fixed roof pitch within a few degrees of the optimum usually loses little energy.
- Using magnetic south from a compass. The orientation here is relative to true south.
Frequently asked questions
What angle should solar panels be?
Your latitude is the year-round optimum. Practical rooftop installs usually follow the roof pitch; the yield loss under 10° off-optimum is small.
Should I adjust panel angle seasonally?
If it's easy (ground mount): +15° in winter, −15° in summer gains ~5–8% annually. On a roof, the access risk and labor usually aren't worth it.