Find a starting tilt angle for your solar panels based on your location’s latitude. Our free solar panel angle calculator estimates annual, summer, and winter tilt angles, converts roof pitch into degrees, and helps you compare your roof slope with the suggested panel angle. Use the results to plan a fixed rooftop or ground-mounted solar installation. The angles are preliminary estimates, not guaranteed maximum-output settings.
Estimate annual, summer, and winter solar panel tilt angles from your latitude. Compare the result with your roof pitch.
Latitude-based planning estimate
Estimates are based on latitude, not a weather simulation. Actual best tilt and azimuth depend on local solar irradiance, shade, roof orientation, mounting constraints, seasonal goals, and weather. A roof's pitch does not establish its compass direction. Ask a qualified installer to assess structural, electrical, and roof safety before installation. No live electrical or roof-work instructions are provided.
Find a starting tilt angle for fixed solar panels using your location’s latitude. The calculator also provides seasonal estimates and helps you compare the recommended angle with your roof pitch.
STEP 01
Enter your location’s latitude in degrees. Use a positive value for locations north of the equator and a negative value for locations south of it. Latitude determines the starting point for the annual tilt estimate.
STEP 02
If you know your roof pitch, enter its rise per 12 inches of horizontal run. For example, a 6/12 roof rises 6 inches for every 12 inches horizontally. The calculator converts this slope into degrees for comparison.
STEP 03
Check the annual, summer and winter tilt estimates, along with the suggested equator-facing direction. Use these results for preliminary planning. A qualified installer can assess whether a different angle is more suitable for your roof.
The results describe panel geometry and approximate seasonal adjustments. They do not predict annual electricity production or account for local weather and shading.
The annual result uses the absolute value of your latitude as a starting tilt angle. For example, a location at 35° north latitude produces an annual estimate of 35° from horizontal. This is a planning rule, not a guarantee of maximum yearly energy output.
The summer estimate is 15° lower than the latitude-based annual angle, with a minimum of 0°. A flatter panel generally receives sunlight more directly when the sun is higher in the sky. This adjustment is approximate and assumes the panels can be repositioned.
The winter estimate is 15° higher than the annual angle, capped at 90°. A steeper angle can better align with the lower winter sun. Snow, wind exposure, mounting restrictions and local weather may make a different angle preferable.
Roof pitch describes the slope of a roof. The calculator converts rise-over-run measurements into degrees from horizontal. A roof with a 6/12 pitch has an angle of approximately 26.6°. This lets you compare the existing roof slope with the latitude-based recommendation.
For typical fixed installations, panels in the Northern Hemisphere generally face toward the south, while panels in the Southern Hemisphere generally face toward the north. The suggested direction is toward the equator, not necessarily the best direction for every property. Shading, roof geometry and local electricity-use patterns can affect the choice.
Our solar panel angle calculator uses your geographic latitude to estimate a starting tilt angle for fixed solar panels. It also provides simplified summer and winter adjustments.
Solar Panel Tilt Angle Formula
Annual tilt estimate = |Latitude|
Summer tilt estimate = max(0°, |Latitude| − 15°)
Winter tilt estimate = min(90°, |Latitude| + 15°)
The annual estimate follows a common latitude-based approach described by the U.S. Department of Energy. The seasonal adjustments are simplified planning assumptions, not exact optimized angles.
Quick Calculation Example
For a home at 35° north latitude:
Annual tilt: 35°
Summer tilt: 20°
Winter tilt: 50°
Suggested direction: South
If the roof has a 6/12 pitch, its slope is approximately 26.6°. That is 8.4° flatter than the annual estimate. This difference does not automatically mean the roof needs additional mounting hardware.
Latitude Is a Starting Point: Latitude helps estimate the sun’s seasonal path. However, the angle that produces the most electricity can differ from the latitude-based estimate because of local weather and installation conditions.
Roof Pitch Matters: A roof-mounted solar array often follows the existing roof slope. Changing that angle may require additional mounting equipment, so the potential production benefit should be evaluated against installation complexity.
Tilt and Direction Are Different: Tilt is the angle above horizontal. Direction, or azimuth, describes where the panels face. Both influence sunlight exposure, along with nearby shading and local weather.
Verify Actual Energy Production: The calculator estimates angles, not electricity output. Compare potential tilt settings with NREL PVWatts or consult a qualified solar installer before choosing a final mounting design.
Fixed solar panels remain at the same angle throughout the year. This is a common approach for residential rooftop installations.
The annual latitude-based estimate provides a starting point, but the existing roof slope, shading and local weather may support a different fixed angle. A site-specific production estimate is more useful than assuming every roof must match its latitude exactly.
Adjustable mounts allow the panel angle to change between seasons. A flatter summer angle and steeper winter angle may help capture sunlight as the sun’s position changes.
However, seasonal adjustments require suitable mounting equipment and may introduce additional maintenance and structural considerations. The estimated energy benefit should be evaluated before choosing an adjustable system.
Panel tilt affects how directly sunlight reaches a solar array, but it is not the only factor that determines electricity generation.
Determines the starting panel tilt.
Panel direction affects sunlight exposure.
Roof pitch influences panel tilt.
Shadows and clouds reduce sunlight.
Tilt affects solar energy production.
Clear answers to common questions about solar angle adjusments.
A common starting point is to set the panel tilt approximately equal to the location’s latitude. However, the best angle depends on local sunlight, weather, roof slope, shading and orientation. Many residential roofs can perform well without matching the latitude-based estimate exactly.
Enter your latitude into the calculator. The annual estimate equals the absolute latitude. The calculator subtracts 15° for summer and adds 15° for winter, keeping results between 0° and 90°. These seasonal values are simplified planning estimates rather than guaranteed optimal settings.
A 30° tilt can be suitable for many locations. The U.S. Department of Energy notes that south-facing roofs with slopes between 15° and 40° often perform well. However, local conditions and roof orientation determine whether 30° is appropriate for a particular installation.
In the Northern Hemisphere, south-facing panels are generally a useful starting point. In the Southern Hemisphere, north-facing panels generally face toward the equator. Other directions may still be suitable depending on roof geometry, shading and electricity-use patterns.
Most fixed rooftop systems do not require seasonal adjustment. Adjustable systems may use steeper winter angles, but the benefit depends on location, weather and mounting design. Do not attempt to modify rooftop solar mounting hardware yourself; consult a qualified installer.
Yes. Roof pitch influences the tilt angle of roof-mounted panels and therefore how sunlight reaches them. However, a roof with a different slope from the latitude-based estimate may still produce substantial electricity. Orientation, shading and local weather must also be considered.
Explore these free tools to plan your solar energy system with more detailed estimates.
Estimate daily, monthly and annual solar electricity generation using system size and sunlight assumptions.
Explore illustrative solar system costs based on capacity and installation assumptions.
Estimate potential installation expenses and understand the factors that influence solar project budgets.
Important: This content provides general solar planning information. It does not replace professional structural, electrical or solar installation assessment. Consult a qualified installer and relevant local authorities before making mounting or electrical decisions.