Brian Litz TOP Gun Formula Calculator

Calculate expected precision and recoil characteristics for your rifle configuration.

About the TOP Gun Formula

The TOP Gun Formula (Theory Of Precision for Guns) developed by Bryan Litz predicts the expected precision capability of a rifle system based on its physical characteristics.

The formula correlates muzzle energy and rifle weight to expected group size:

Expected MOA = (Muzzle Energy [ft-lbs] / Rifle Weight [lbs]) / 200

This provides a baseline expectation for precision, helping shooters understand whether their rifle is performing to its mechanical potential or if there's room for improvement.

Rifle Configuration

Enter your rifle and ammunition specifications

Total weight including scope and accessories

Bullet weight

Velocity at the muzzle

Leave empty for automatic estimation

Enter your rifle configuration and click Calculate to see results