Sun Path & Shadow Calculator
Find the sun's altitude and azimuth for any latitude, date, and time — and the length and direction of the shadow it casts. Ideal for solar studies and site analysis.
Time is treated as local solar time (solar noon = sun due south in the Northern Hemisphere). For clock time, adjust for your time zone, longitude, and daylight saving.
Sun Angles and Shadows for Site Analysis
Understanding where the sun sits in the sky is the foundation of good passive design, daylighting, and overshadowing studies. The sun's position is described by two angles: altitude (how high above the horizon it is) and azimuth (its compass bearing, measured clockwise from north). This calculator derives both from the solar declination for your chosen date and the hour angle for your chosen time.
From the altitude it also computes how far a shadow will stretch: a low sun near sunrise or sunset throws long shadows, while a high midday sun casts short ones. The shadow always falls in the direction opposite the sun, so the tool reports the shadow's length in feet and its compass bearing — handy for checking solar access, panel placement, and how a new building might shade its neighbors.
Frequently Asked Questions
How do I calculate the sun's angle?
The solar altitude comes from your latitude, the sun's declination for the date, and the hour angle for the time: sin(altitude) = sin(lat)·sin(declination) + cos(lat)·cos(declination)·cos(hour angle). Take the inverse sine to get the angle in degrees.
How do I find shadow length?
Divide the object's height by the tangent of the sun's altitude: shadow length = height ÷ tan(altitude). When the sun is low the tangent is small, so shadows are long; when the sun is overhead the shadow shrinks toward zero.
What is solar azimuth?
Solar azimuth is the sun's compass bearing, measured in degrees clockwise from north. An azimuth of 90° is due east, 180° is due south, and 270° is due west, so it tells you which way to face to look at the sun.
From Sketch to Clean Plan, or to a Measured DXF
These utilities pair with our AI tools: redraw a sketch or photo as a clean, labeled plan here, or design a measured plan with PDF and DXF for AutoCAD in Plan Chat (same account).