# Angle of Depression Calculator

URL: https://speedycalculator.com/calculators/construction/angle-of-depression/
Last updated: 2026-10-25

> The angle of depression calculator finds the angle below the horizontal from an observer to a lower point from the height difference and horizontal distance, plus the line-of-sight distance.

## Inputs

- Height difference (m, ft, cm, in, yd)
- Horizontal distance (m, ft, cm, in, yd)

## Results

- Angle of depression
- Line-of-sight distance
- Slope

## Formula

```
Angle = atan(height difference ÷ horizontal distance)
Line of sight = √(h² + d²)
```

## Explanation

The angle of depression is measured downwards from a horizontal line at the observer's eye to an object below – for example from a roof to a point on the ground, or from a lighthouse to a ship. It equals the angle of elevation measured from the object back up to the observer.

### How to use the Angle of Depression Calculator

- **Height difference**
- **Horizontal distance**
- Every result field is editable: type into **Angle of depression** and **Horizontal distance** plus every other field update to match.

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the height difference and the horizontal distance. Type an angle into the result to find the distance.

### Tips for an accurate estimate

- Measure angles with a digital angle finder or sliding bevel, not by eye.
- Make a test cut in scrap before cutting expensive stock.
- Small angle errors add up over many joints – check the first assembly before cutting the rest.
- Keep a written list of the dimensions and angles you set on the saw or machine.

### Common mistakes to avoid

- Reading the saw scale as the angle from the edge rather than from square.
- Rounding intermediate results too early.
- Mixing degrees and percent grade.

### Inputs explained

FieldWhat to enterHeight differenceUnits: m, ft, cm, in, ydHorizontal distanceUnits: m, ft, cm, in, yd

### What each result means

- **Angle of depression** = deg(atan([Height difference]÷[Horizontal distance]))
- **Line-of-sight distance** = sqrt([Height difference]^2 + [Horizontal distance]^2)
- **Slope** = [Height difference]÷[Horizontal distance]×100

### Example values

How the main result changes when **Horizontal distance** changes and everything else stays at the example values above:

Horizontal distance (m)Angle of depression (°)2550.1937.538.665030.9662.525.647521.810016.7

## Worked example

Inputs — Height difference: 30 m; Horizontal distance: 50 m.

Results — **Angle of depression = 30.96 °**; Line-of-sight distance = 58.31 m; Slope = 60 %.

## FAQ

**Is the angle of depression equal to the angle of elevation?**
Yes – they are alternate angles between parallel horizontal lines.

**How do I find the distance from the angle?**
Distance = height ÷ tan(angle).

**What formula does the Angle of Depression Calculator use?**
Angle = atan(height difference ÷ horizontal distance).