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Angle of Depression Calculator.

Calculate a right-triangle angle from vertical drop and horizontal distance.

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Set your values

Results update as you type.

02 / ANSWER

Vertical drop

Horizontal distance

Result

0.0000

Results use only the stated formula and entered units; they are not building-code, equipment-sizing, or structural design advice.

Use Cases

Construction and Surveying

Determine the angle of a slope or ramp when you know the vertical drop and horizontal run, useful for grading, drainage, or accessibility design.

Example: A ramp drops 2 feet over a horizontal distance of 10 feet, giving an angle of about 11.3°.

Photography and Observation

Calculate the angle at which a camera or observer looks down to capture a subject at a known distance and height difference.

Example: From a balcony 15 m high, looking at a point 20 m away horizontally, the depression angle is about 36.9°.

Frequently Asked Questions

What is the angle of depression?: The angle of depression is the angle formed between a horizontal line from the observer's eye and the line of sight to an object below. In this calculator, it's computed from the vertical drop and horizontal distance using trigonometry.
How is the angle of depression calculated?: The calculator uses the arctangent (inverse tangent) of the ratio of vertical drop to horizontal distance. Specifically, angle = arctan(vertical drop / horizontal distance). The result is given in degrees.
What units should I use for vertical drop and horizontal distance?: You can use any consistent units (e.g., feet, meters, inches) for both inputs. The calculator only requires that both are in the same unit to compute the ratio correctly.

Tips & Common Mistakes

Tips

Ensure both inputs are in the same unit (e.g., both feet or both meters) to get an accurate angle.
For very small angles, the result will be close to zero; for very large drops relative to distance, the angle approaches 90°.
Use the angle to verify slope compliance: for example, a 1:10 slope corresponds to about 5.7°.
Double-check your measurements: a small error in vertical drop or horizontal distance can significantly affect the angle, especially for steep angles.

Common Mistakes to Avoid

Mixing units (e.g., feet for drop and meters for distance) without converting, leading to incorrect ratios.
Entering the horizontal distance as the slope length instead of the horizontal run, which would give a different angle.
Forgetting that the angle of depression is measured from the horizontal, not from the vertical, so it's the complement of the angle of elevation from the lower point.

Last updated: August 13, 2026

Use Cases

Construction and Surveying

Determine the angle of a slope or ramp when you know the vertical drop and horizontal run, useful for grading, drainage, or accessibility design.

Example: A ramp drops 2 feet over a horizontal distance of 10 feet, giving an angle of about 11.3°.

Photography and Observation

Calculate the angle at which a camera or observer looks down to capture a subject at a known distance and height difference.

Example: From a balcony 15 m high, looking at a point 20 m away horizontally, the depression angle is about 36.9°.

Frequently Asked Questions

What is the angle of depression?

The angle of depression is the angle formed between a horizontal line from the observer's eye and the line of sight to an object below. In this calculator, it's computed from the vertical drop and horizontal distance using trigonometry.

How is the angle of depression calculated?

The calculator uses the arctangent (inverse tangent) of the ratio of vertical drop to horizontal distance. Specifically, angle = arctan(vertical drop / horizontal distance). The result is given in degrees.

What units should I use for vertical drop and horizontal distance?

You can use any consistent units (e.g., feet, meters, inches) for both inputs. The calculator only requires that both are in the same unit to compute the ratio correctly.

Tips & Common Mistakes

Tips

Ensure both inputs are in the same unit (e.g., both feet or both meters) to get an accurate angle.
For very small angles, the result will be close to zero; for very large drops relative to distance, the angle approaches 90°.
Use the angle to verify slope compliance: for example, a 1:10 slope corresponds to about 5.7°.
Double-check your measurements: a small error in vertical drop or horizontal distance can significantly affect the angle, especially for steep angles.

Common Mistakes to Avoid

Mixing units (e.g., feet for drop and meters for distance) without converting, leading to incorrect ratios.
Entering the horizontal distance as the slope length instead of the horizontal run, which would give a different angle.
Forgetting that the angle of depression is measured from the horizontal, not from the vertical, so it's the complement of the angle of elevation from the lower point.

Use Cases

Construction and Surveying

Determine the angle of a slope or ramp when you know the vertical drop and horizontal run, useful for grading, drainage, or accessibility design.

Example: A ramp drops 2 feet over a horizontal distance of 10 feet, giving an angle of about 11.3°.

Photography and Observation

Calculate the angle at which a camera or observer looks down to capture a subject at a known distance and height difference.

Example: From a balcony 15 m high, looking at a point 20 m away horizontally, the depression angle is about 36.9°.

Frequently Asked Questions

What is the angle of depression?

How is the angle of depression calculated?

What units should I use for vertical drop and horizontal distance?

You can use any consistent units (e.g., feet, meters, inches) for both inputs. The calculator only requires that both are in the same unit to compute the ratio correctly.

Tips & Common Mistakes

Tips

Ensure both inputs are in the same unit (e.g., both feet or both meters) to get an accurate angle.
For very small angles, the result will be close to zero; for very large drops relative to distance, the angle approaches 90°.
Use the angle to verify slope compliance: for example, a 1:10 slope corresponds to about 5.7°.
Double-check your measurements: a small error in vertical drop or horizontal distance can significantly affect the angle, especially for steep angles.

Common Mistakes to Avoid

Mixing units (e.g., feet for drop and meters for distance) without converting, leading to incorrect ratios.
Entering the horizontal distance as the slope length instead of the horizontal run, which would give a different angle.
Forgetting that the angle of depression is measured from the horizontal, not from the vertical, so it's the complement of the angle of elevation from the lower point.