This program helps convert inches or centimeters held at a typical arm's length (25 inches or 64 cm) to angular
size in degrees. Don't guess, use a ruler! (Also see "Elevation - angle helper")
×
How to Use This Tool
This tool helps researchers determine the true angular size of an observed object by comparing it to a physical
measurement taken at arm's length.
Hold a ruler out at arm's length (standardized here as 25 inches or 64 cm) and measure how large the object
appears. Enter that measurement into either the inches or centimeters field to instantly calculate its angular
size in degrees.
