Enter the peripheral speed (m/s) and the upstream speed (m/s) into the Calculator. The calculator will evaluate the Apparent Angle. 

Apparent Angle Formula

AA = atan (Vp/V) * 57.2958


  • AA is the Apparent Angle (degrees)
  • Vp is the peripheral speed (m/s)
  • V is the upstream speed (m/s)

To calculate the Apparent Angle, take the arc tangent of the peripheral speed over the upstream speed, then multiply by 57.2958 to convert to degrees.

How to Calculate Apparent Angle?

The following steps outline how to calculate the Apparent Angle.

  1. First, determine the peripheral speed (m/s). 
  2. Next, determine the upstream speed (m/s). 
  3. Next, gather the formula from above = AA = atan (Vp/V) * 57.2958.
  4. Finally, calculate the Apparent Angle.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

peripheral speed (m/s) = 50

upstream speed (m/s) = 30