Looking for the Wndsn store? This way, please: Limited editions tools and embroidered morale patches from the Wndsn Expedition Team.

Wndsn Range Calculator

High-precision range calculator. Companion to Wndsn Telemeters: Low tech, high utility graphical distance computers from the Wndsn applied science lab.

The distance d from eye to measurement, and the height s of the measurement, form two sides of a right triangle, and thus determine an angle α, opposite of s. Making use of these values we can extrapolate and determine the distance D to the measured object S.

                                        S
                              +         S
                   +  s                 S
         +       α    s                 S
Eye ddddddddddddddddd s                 S
    DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD S

Input

Determine D (use any unit, but consistently (cm, mm, inches, etc.) for S, d, s):
Reset

Reference

1        rad =  57.3    deg
6.2832   rad = 360      deg = 6283.2   mil = 21,600     minutes (moa)
0.017453 rad =   1      deg =   17.453 mil =     60     minutes (moa)
                 0.0573 deg =    1     mil =      3.438 minutes (moa)

See also