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Current Sun Position Calculator

Reviewed by Calculator Editorial Team

The Current Sun Position Calculator determines the sun's azimuth and altitude angles for any given location, date, and time. This information is essential for solar energy applications, astronomy, and outdoor activities.

What is Sun Position?

The sun's position in the sky is defined by two key angles: azimuth and altitude.

  • Azimuth is the compass direction from which the sun is shining, measured in degrees clockwise from north (0° to 360°).
  • Altitude is the angle of the sun above the horizon, measured in degrees (0° at horizon to 90° at zenith).

These angles change throughout the day and vary with seasons and latitude. Understanding sun position helps in optimizing solar panel placement, predicting daylight hours, and planning outdoor activities.

How to Use This Calculator

  1. Enter your location's latitude and longitude in decimal degrees.
  2. Select the current date and time.
  3. Click "Calculate" to get the sun's azimuth and altitude.
  4. Review the results and chart showing the sun's path.

For best accuracy, use precise coordinates and local time. The calculator uses the solar zenith angle method for calculations.

Formula Used

The calculator uses the following formulas to determine sun position:

  1. Calculate the day of the year (n):
    2. n = day of year (1-366)
  2. Calculate solar declination (δ):
    3. δ = 23.45° * sin(360° * (284 + n) / 365)
  3. Calculate hour angle (H):
    4. H = 15° * (local time - 12)
  4. Calculate solar zenith angle (θ):
    5. θ = arccos(sin(φ) * sin(δ) + cos(φ) * cos(δ) * cos(H))
  5. Calculate solar altitude (α):
    6. α = 90° - θ
  6. Calculate solar azimuth (A):
    7. A = arctan2(sin(H), cos(H) * sin(φ) - tan(δ) * cos(φ))

Worked Example

Let's calculate the sun position for New York City (40.7128° N, 74.0060° W) on June 21 at 12:00 PM.

  1. Day of year (n): 172 (June 21)
  2. Solar declination (δ): 23.45° * sin(360° * (284 + 172) / 365) ≈ 23.44°
  3. Hour angle (H): 15° * (12 - 12) = 0°
  4. Solar zenith angle (θ): arccos(sin(40.7128°) * sin(23.44°) + cos(40.7128°) * cos(23.44°) * cos(0°)) ≈ 49.26°
  5. Solar altitude (α): 90° - 49.26° ≈ 40.74°
  6. Solar azimuth (A): arctan2(0, cos(0°) * sin(40.7128°) - tan(23.44°) * cos(40.7128°)) ≈ 180° (south)

At this time, the sun is directly overhead (azimuth 180°) with an altitude of 40.74°.

Interpreting Results

The calculator provides:

  • Azimuth: Indicates the sun's compass direction. 0° is north, 90° is east, 180° is south, and 270° is west.
  • Altitude: Shows how high the sun is in the sky. Higher values mean more direct sunlight.

Use these values to:

  • Position solar panels for maximum efficiency.
  • Plan outdoor activities based on daylight availability.
  • Understand seasonal variations in sunlight intensity.

Frequently Asked Questions

How accurate is this calculator?
The calculator uses standard astronomical formulas and provides accurate results within ±1° for most locations and times.
Does this work for any location?
Yes, the calculator accepts any valid latitude and longitude coordinates worldwide.
What time zone should I use?
Use the local time of the location you're calculating for. The calculator does not adjust for daylight saving time.
Can I use this for solar energy projects?
Yes, the sun position data is essential for solar panel installation and energy yield estimation.
How often should I recalculate sun position?
For most applications, recalculating every few hours is sufficient, but for precise tracking systems, more frequent updates may be needed.