PBRCalc is mobile app with two functions ...

1) Muzzle Energy Calculation:
Select one of 'Velocity @ Muzzle', 'Projectile Weight' or 'Energy @ Muzzle' labels to set the value to be calculated and the required value will be displayed when data is entered into the other two. In most cases, it will probably be the Muzzle Energy value that requires calculation.

2) Point Blank Range Calculations:
Enter values for 'Velocity @ Muzzle', 'Sight Height', 'Ballistic Coefficient' (and the appropriate Drag Law) together with the 'Killzone' diameter required.
The Nominal Point Blank Range together with the appropriate Far and Near Zeros will then be calculated and displayed. Alternatively, enter a value for the Far (or Near) Zero Range to calculate the corresponding Killzone diameter together with the corresponding PBR.