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News Flash

Jan 2022: Release of app update.

Feb 2021: Added Utilities to calculate Stability Factor, Spin Drift, Coriolis and Eotvos effects, and speed of sound. 

Coriolis Effect

There are 2 Earth Rotation Effects that are of interest in external ballistics.  Both are a subset of what is known mathematically as Coriolis Acceleration.  The Coriolis Effect of ballistics manifests itself as an apparent drift to the right of the target in the Northern Hemisphere, and to the left in the Southern Hemisphere.  It affects shots in all directions and depends only on latitude.  It has maximum impact at the poles, and the effect is zero at the equator.

deflection (ft) = 0.000072722 * distance(ft) * Sin(latitude) * time of flight(seconds)

All values must be entered by the user. Otherwise zeros will result.


Latitude (degree)
Distance (yards)
Time of Flight (seconds)



Coriolis Effect (Feet) POI to the Right


The deviation in MOA is calculated using the Teunissen Equation, developed by ameteur Dutch physicist C. Teunissen. The beauty of this equation is that the answer is directly usable in a scope with moa windage markings. Deviation (moa) = 0.25 * tof * sin(latitude)


Deviation (MOA) POI to the Right