Solar Panel Tilt Calculator
Find the optimal tilt angle for your latitude — summer, winter, or year-round optimization.
| Configuration | Tilt | Annual kWh |
|---|---|---|
| Flat (0°) | 0° | 11,300 |
| Summer optimal (20°) | 20° | 11,795 |
| Year-round optimal (33°) | 33° | 12,487 |
| Winter optimal (50°) | 50° | 13,080 |
Production estimates assume 4.5 avg peak sun hours and 86% system efficiency. Actual values vary by location.
How to Use This Calculator
Enter your latitude
Your latitude in degrees north is the foundation of tilt optimization — the sun's path across your sky changes with latitude. Major US cities: Miami 25.8°, Los Angeles 34.1°, Atlanta 33.7°, Denver 39.7°, New York 40.7°, Chicago 41.9°, Seattle 47.6°. Find your exact latitude on Google Maps: right-click your location and the coordinates appear (first number is latitude).
Choose what to optimize for
Select whether you want to maximize production in summer, winter, spring/fall, or year-round. For most grid-tied systems, year-round optimization gives the best annual kWh and financial return. Winter optimization makes sense if you have time-of-use electricity rates with peak pricing in winter months, or if you want to maximize self-consumption during the period when your panels produce least.
Enter system size
Your system size in kW lets the calculator show you the actual production difference in kWh — not just percentages — between flat, summer-optimal, year-round optimal, and winter-optimal tilts.
Read the comparison table
The comparison table shows annual production estimates at all four tilt configurations. For most US locations, the difference between flat (0°) and year-round optimal tilt is 10-15% — meaningful over 25 years but not dramatic. The "gain vs. flat" percentage in the result card shows the specific benefit for your latitude.
The Formula
The fundamental principle: to maximize solar capture, panels should face the sun as directly as possible. The sun's elevation angle changes with both latitude and season. At latitude 35°, the sun is 78° above the horizon at summer solstice noon and only 32° above horizon at winter solstice noon. A 35° tilt is the best compromise for year-round production at this latitude.
The production gain estimates assume average annual weather patterns. High-latitude locations (above 45°) see the most benefit from tilt optimization because the sun stays lower in the sky year-round.
Example
10 kW system in Denver, CO (latitude 39.7°)
Denver's high altitude and predominantly sunny skies make tilt optimization particularly valuable. A homeowner wants to know whether adjusting their fixed roof tilt is worth the consideration.
Tilt Recommendations
Annual Production Impact
At $0.14/kWh, the 1,900 kWh/yr gain from proper tilt equals $266/year in extra production. Over 25 years, that's $6,650 in additional electricity value — meaningful but not a game-changer. The bigger takeaway: if you already have a 30° or 35° pitched roof, you're close to optimal and don't need to modify anything.