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THE FEUTEX TOOLKIT

Apparent Angular Diameter

Calculate the angle subtended by a circular object of known diameter and distance.

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01 Your input
02 Your result
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FormulaAngular diameter = 2*atan(d/(2*r))*180/PI; Angular diameter = 2*atan(d/(2*r))*648000/PI
Sources and model references

Worked example

Inputs

Object diameter
1 same length units
Distance
100 same length units

Expected results

Angular diameter
0.5729530206 degrees
Angular diameter
2062.630874 arcsec

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Calculate the angle subtended by a circular object of known diameter and distance.
  2. Set object diameter, distance in the indicated units.
  3. Calculate and compare angular diameter, angular diameter.

Try this example

{
  "d": 1,
  "r": 100
}

Accuracy and scope

Idealized educational model. Enter measured values in the displayed units; real systems may require additional corrections.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.