Calculate precise sun position for any location, date, and time. Essential for solar panel placement, shading analysis, and optimal system design.
Understanding the sun's position at any time of day and year is fundamental to solar design. This calculator gives you precise altitude and azimuth data for shading analysis, panel orientation, and row spacing calculations.
Understanding sun position is fundamental to solar design. Use this calculator when:
Input your location's latitude and longitude, or use the auto-detect feature for your current location.
Choose the date you want to analyze, or use today's date as the default.
Select a specific time or view the full-day sun path from sunrise to sunset.
Review the solar altitude (height above horizon) and azimuth (compass direction) angles displayed in the results.
Use the results for panel tilt optimization, shading analysis, or site survey documentation.
The angle of the sun above the horizon in degrees. 0° = horizon, 90° = directly overhead. Determines shadow length and solar intensity.
The compass bearing of the sun in degrees. 0° = North, 90° = East, 180° = South, 270° = West. Determines which direction shadows point.
The angle between the sun and the celestial equator, ranging from -23.45° to +23.45° throughout the year. Drives seasonal variation.
Exact times when the sun crosses the horizon, determining available solar production hours for the selected date and location.
The time when the sun reaches its highest altitude — the moment of maximum solar intensity and shortest shadows.
Our calculator uses established astronomical formulas to compute the sun's position based on your geographic coordinates, date, and time.
Worked example: At 35°N latitude (Charlotte, NC) on June 21 (summer solstice): Solar noon elevation angle = 90° − 35° + 23.45° = 78.45°. On December 21 (winter solstice): 90° − 35° − 23.45° = 31.55°. Optimal fixed tilt = latitude = 35°. A 35° tilt captures 98.5% of optimal annual yield. Adjusting to 25° boosts summer output by ~4% but reduces winter generation by ~9%.
Calculations sourced from SurgePV’s Sun Angle Calculator — surgepv.com/tools/sun-angle-calculator/
Maximum sun altitude angles at solar noon for major US cities on key dates.
| City | Latitude | Summer Solstice | Equinox | Winter Solstice |
|---|---|---|---|---|
| Miami, FL | 25.8°N | 87.7° | 64.2° | 40.8° |
| Houston, TX | 29.8°N | 83.7° | 60.2° | 36.8° |
| Phoenix, AZ | 33.4°N | 80.1° | 56.6° | 33.2° |
| Los Angeles, CA | 34.1°N | 79.4° | 55.9° | 32.5° |
| Atlanta, GA | 33.7°N | 79.8° | 56.3° | 32.8° |
| Denver, CO | 39.7°N | 73.8° | 50.3° | 26.8° |
| New York, NY | 40.7°N | 72.8° | 49.3° | 25.8° |
| Chicago, IL | 41.9°N | 71.6° | 48.1° | 24.6° |
| Boston, MA | 42.4°N | 71.1° | 47.6° | 24.1° |
| Seattle, WA | 47.6°N | 65.9° | 42.4° | 18.9° |
The winter solstice (Dec 21) has the lowest sun altitude and longest shadows. If your system is shade-free on this date, it will be shade-free year-round. This is your worst-case design point.
Compasses point to magnetic north, which differs from true north by the magnetic declination (up to 20° in some US locations). Always use true north for azimuth calculations.
Row spacing = panel height / tan(winter solstice altitude). For a 4-foot-high panel in New York (altitude 25.8°), minimum spacing = 4 / tan(25.8°) = 8.3 feet between rows.
80% of daily solar energy is captured between 9 AM and 3 PM. Focus shading analysis on this 6-hour window. Partial morning/evening shade has minimal production impact.
Sun angle data is essential for three things — tilting panels for maximum energy capture, identifying shading from nearby objects, and determining row spacing in ground-mount or flat-roof arrays to avoid inter-row shading.
At solar noon, altitude = 90° - |latitude - declination|. In New York (40.7°N) on the summer solstice (declination +23.45°), solar noon altitude = 90° - |40.7 - 23.45| = 72.75°.
The sun's maximum altitude varies by ±23.45° between summer and winter solstices. The sun is highest on June 21st and lowest on December 21st. This affects daily energy production by 30–50% between seasons.
Azimuth tells you which direction the sun is at any time. For shading analysis, you can determine exactly when a tree or building will cast a shadow on your panels. For panel orientation, you want panels facing true south (180°) in the Northern Hemisphere.
To prevent inter-row shading, calculate the shadow length at winter solstice solar noon. Shadow length = panel height / tan(altitude angle). Add this as minimum row spacing.
The calculator uses solar time (based on actual sun position) rather than clock time. Solar noon may differ from 12:00 PM clock time by up to an hour or more depending on your time zone position and DST.
Convert roof pitch and find optimal solar panel tilt angle.
Estimate peak sun hours and solar irradiance for any location.
Determine the right solar system size for your energy needs.
Calculate the right solar system size based on energy usage.
Design optimal PV string configurations for any inverter.
Measure the environmental impact of your solar installation.
.svg)
