Solar Panel Tilt Angle Calculator
Find the optimal tilt angle for your solar panels based on your latitude, season, and installation goal — maximize your annual energy output for free.
Enter a city or ZIP to auto-fill your latitude below.
How to use this solar panel tilt angle calculator
Enter your location. Type your city or ZIP code to auto-fill your latitude, or enter it manually. Latitude is the single most important input — it determines the angle of the sun above the horizon at your location.
Choose what to optimize for. If your panels run year-round, choose “Maximum annual output.” If you use more energy in summer (air conditioning) or winter (heating), choose accordingly to bias the calculation toward that season.
Select your installation type. Fixed mounts use a single static angle. Single-axis trackers follow the sun east-to-west and can increase output by 25–35%. Dual-axis trackers also adjust for seasonal changes and can add another 5–10%.
Select your roof pitch if you’re mounting panels on an existing roof. The calculator will show you how far your roof pitch is from the ideal tilt angle and whether additional racking is needed.
Click Calculate to get your optimal angle, seasonal adjustments, panel direction, and a visual diagram of the recommended tilt.
How is the optimal solar panel angle calculated?
The sun’s position in the sky changes with the seasons because Earth’s axis is tilted 23.5° relative to its orbit. To maximize energy capture, solar panels should be angled perpendicular to the incoming sunlight — and since the sun’s angle changes, the ideal panel tilt depends on both your latitude and the time of year.
Summer optimum = Latitude − 15°
Winter optimum = Latitude + 15°
Equinox optimum = Latitude (exact)
Southern hemisphere: same formula, but panels face North instead of South
These formulas are accurate for most residential and commercial installations in temperate climates. For very high latitudes (above 60°) or locations with unusual weather patterns, a more detailed irradiance simulation using local weather data is recommended.
The direction panels face matters equally: in the Northern hemisphere, panels should face true south (not magnetic south). In the Southern hemisphere, they should face true north. Deviations of up to 15° from true south/north cause less than 5% energy loss — important to know if your roof isn’t perfectly oriented.
Optimal solar panel tilt by latitude — quick reference
| City (approx. latitude) | Annual tilt | Summer tilt | Winter tilt | Panel faces |
|---|---|---|---|---|
| Miami, FL (25°N) | 25° | 10° | 40° | True South |
| Houston, TX (30°N) | 29° | 15° | 45° | True South |
| Los Angeles, CA (34°N) | 33° | 19° | 49° | True South |
| Denver, CO (40°N) | 38° | 25° | 55° | True South |
| New York, NY (41°N) | 39° | 26° | 56° | True South |
| Seattle, WA (47°N) | 44° | 32° | 62° | True South |
| Sydney, AU (34°S) | 33° | 49° | 19° | True North |
| Melbourne, AU (38°S) | 36° | 53° | 23° | True North |
These are general estimates. Use the calculator above for your exact latitude. Local shading, weather patterns, and installation constraints may require adjustments.
Solar panel tilt vs. roof pitch — does your roof work?
Most residential roofs in the US have a pitch between 4/12 (18.4°) and 8/12 (33.7°). For homeowners in the 30°–45°N latitude band, this range often coincides reasonably well with the optimal annual tilt angle — which is why roof-mounted solar installations work well across much of the country.
If your roof pitch is significantly lower than your optimal tilt (say, a 2/12 pitch roof in Denver at 38° optimal), you have two options: use tilt-up racking to raise the panels to the ideal angle, or accept a modest energy reduction. For every 10° of deviation from the optimal tilt, you typically lose 1–3% of annual energy output — often worth accepting to avoid the added cost and wind load of tilt racks.
| Roof pitch | Angle (°) | Best latitude match | Tilt rack needed? |
|---|---|---|---|
| 2/12 | 9.5° | Tropics (0°–15°) | Yes, for most US locations |
| 4/12 | 18.4° | 15°–25° (South FL, HI) | Often recommended |
| 5/12 | 22.6° | 25°–30° (TX, GA) | Optional |
| 6/12 | 26.6° | 30°–35° (CA, NC) | Usually not needed |
| 7/12 | 30.3° | 35°–40° (TN, CO) | No |
| 8/12 | 33.7° | 38°–43° (NY, IL) | No |
| 10/12 | 39.8° | 45°–50° (MN, WA) | No |