Enter the distance, length, and angle into the calculator to determine the angular size of a triangle.

Angular Size Formula

The following formula is used to calculate the angular size.

D = 2 * L * tan (a/2) 
  • Where D is the angular size
  • L is the radius/length depicted below
  • a is the angle depicted below

To calculate the angular size, multiply 2 times the length by the tangent of half the angle.

Angular Size Definition

An angular size is a value of the length of a field of view.

Angular Size Example

How to calculate angular size?

  1. First, determine the radius.

    Measure the radius.

  2. Next, determine the angle.

    Measure the angle.

  3. Finally, calculate the size.

    Calculate the angular size using the equation above.


What is an angular size?

An angular size is a value of length that represents the total length of a field of view from a point of a triangle, a certain radius, and certain angle. This can be seen as D in the above depiction.

angular size calculator