🔭 Angle of Depression Calculator
Calculate the angle of depression from an elevated point down to a target, based on height and horizontal distance.
What Is the Angle of Depression?
The angle of depression is the angle measured downward from a horizontal line of sight to an object below the observer, for example looking down from a crane, roof, or survey tower to a point on the ground.
How It’s Calculated
Because the horizontal sightline and the vertical drop form a right triangle with the line of sight, the angle of depression equals arctan(height / horizontal distance). This is mathematically identical to the angle of elevation an observer at the target would measure looking back up, since the two lines are parallel (alternate interior angles).
This calculator is useful in surveying, construction site layout, and basic trigonometry problems. For general planning and educational purposes only; for legal survey work, use a licensed surveyor and calibrated instruments.