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.
Last 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.
Formula
Tilt_annual ≈ |latitude| Tilt_winter ≈ |latitude| + 15° Tilt_summer ≈ |latitude| − 15°
| Symbol | Meaning | Unit |
|---|---|---|
φ | Site latitude | ° |
β | Panel tilt from horizontal | ° |
γ | Azimuth (0° = north, 180° = south) | ° |
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.
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.