Estimate shadow length from object height and sun elevation angle. This calculator can also estimate object height from a known shadow, calculate sun angle from height and shadow, and show useful ratios for solar planning, gardening, photography, and outdoor layout.
Object height:
Enter the height of the object casting the shadow, such as a person, tree, pole, fence, wall, or building.
Sun elevation angle:
Enter the angle of the sun above the horizon. A low angle means a longer shadow.
Shadow length:
The calculator uses basic right-triangle trigonometry to estimate the shadow length on the ground.
Reverse calculations:
You can also calculate object height from a shadow, or calculate the sun angle from height and shadow length.
A shadow length calculator is useful for gardening, solar planning, outdoor seating, shade studies, photography, fence and tree planning, building layout, patio design, and estimating how far a shadow may reach.
This calculator gives a simple estimate. Actual shadow length can vary with ground slope, terrain, nearby objects, solar azimuth, object shape, and local horizon conditions.
Your result estimates the relationship between object height, shadow length, and sun elevation angle. A shadow ratio above 1 means the shadow is longer than the object height. A ratio below 1 means the shadow is shorter than the object height.
Divide the object height by the tangent of the sun elevation angle. Lower sun angles create longer shadows.
A 45-degree sun elevation angle makes the shadow length about equal to the object height on flat ground.
The sun is lower near sunrise and sunset, so light hits the object at a shallow angle and creates a longer shadow.
Yes. It can estimate basic shadow length, but actual shade also depends on sun direction, object width, terrain, and season.