Solar Angle & Sun Position Calculator

A solar angle calculator converts latitude, longitude, date, local time, and UTC offset into the apparent position of the sun in the sky. The two values most people need are solar azimuth and solar elevation. Azimuth tells you the compass direction of the sun, while elevation tells you how high the sun is above the horizon.

This matters when setting a fixed solar panel, planning a building overhang, checking winter shadows, timing a photo shoot, arranging greenhouse rows, or teaching Earth-sun geometry. The calculator also returns solar noon, sunrise, sunset, day length, zenith angle, solar declination, equation of time, and a basic panel incidence angle.

Solar azimuth is measured clockwise from true north. An azimuth of 90 degrees points east, 180 degrees points south, and 270 degrees points west. This convention matches common solar, GIS, and architectural workflows, but it is different from some older surveying angle conventions.

Solar elevation is the apparent angle above the horizon. A value near 0 degrees means the sun is on the horizon. A value near 90 degrees means the sun is almost overhead. The zenith angle is the complement of elevation: zenith equals 90 degrees minus elevation.

The calculator uses the NOAA-style solar position approximation. It converts the local clock time to UTC, computes Julian day and Julian century, then derives the sun's apparent longitude, declination, equation of time, hour angle, zenith angle, and azimuth. Atmospheric refraction is applied to the displayed elevation angle so low sun positions are closer to what an observer sees.

Sunrise and sunset use the standard official solar zenith of 90.833 degrees, which includes the approximate solar radius and atmospheric refraction near the horizon. At high latitudes the formula can identify polar day, when the sun does not set, and polar night, when the sun does not rise.

The same latitude and longitude can produce a wrong result if the UTC offset is wrong. Solar calculations depend on the instant in time, not just the date printed on a calendar. If daylight saving time is active, use the daylight saving UTC offset. If standard time is active, use the standard offset.

Longitude also affects solar noon. Places near the western edge of a time zone often experience solar noon noticeably later by clock time than places near the eastern edge. That is why two cities with the same civil time can have different sun angles at the same clock minute.

Solar installers use azimuth and elevation to understand where the sun is relative to an array. In the northern hemisphere, fixed panels commonly face true south; in the southern hemisphere, they commonly face true north. The panel incidence angle in the results estimates how directly sunlight strikes the panel plane at the selected time.

This tool does not replace full production modeling. It does not include shade, weather, aerosols, snow, soiling, inverter clipping, roof geometry, or local utility rules. Use it as a fast geometry check, then use a dedicated solar production model when energy yield or financial return matters.

Photographers use sun azimuth to predict the direction of light and solar elevation to estimate how harsh or low the light will be. Architects use the same values to evaluate facade exposure, passive solar gain, glare, seasonal shading, and overhang performance. Farmers and greenhouse designers use day length and low-sun angles to plan crop rows, tunnel orientation, and winter light access.

For these planning tasks, a clean coordinate-based calculator is often faster than a large map application. You can paste coordinates from a survey, GIS layer, drone mission, or GPS device and immediately get the key solar geometry values.

The NOAA-style approximation is suitable for solar planning, education, architecture studies, photography planning, and field checks. It is not a certified astronomical ephemeris and should not be used as the only source for legal, navigation, observatory, or safety-critical decisions.

Near sunrise and sunset, small differences in pressure, temperature, local horizon height, and terrain can shift observed times. Mountain ridges, buildings, forests, and roof obstructions are not included. For site-specific shading, pair this result with field measurements, a horizon survey, or a dedicated solar design package.