Calculadora de Coeficiente Balístico
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
BC = lb/(Cd·d²)
About this calculator
The Ballistic Coefficient Calculator determines the ballistic coefficient (BC) of a projectile, a measure of its ability to overcome air resistance. BC is calculated from the projectile's mass (in pounds), drag coefficient (Cd), and diameter (in inches). The formula used is BC = m / (Cd × d²). A higher BC means a more aerodynamic projectile, retaining velocity and trajectory better over distance.
This tool is useful for sport shooters, hunters, and ballistics enthusiasts who want to compare different projectiles or predict their performance at long ranges. The ballistic coefficient is essential for calculations of bullet drop, wind drift, and residual kinetic energy. With BC, you can use trajectory software to adjust your scope accurately.
When using the calculator, input correct values for mass, Cd, and diameter. Remember that Cd can vary with speed and projectile shape; for accurate results, use tabulated Cd values for the expected velocity range. The diameter should be the projectile caliber in inches. The calculator assumes consistent units (pounds and inches).
Cautions: BC is not constant; it changes with velocity (especially at supersonic speeds). Advanced models use velocity-dependent BC. Additionally, empirical BC (obtained by field measurement) may differ from calculated due to simplifications. Use this calculator as an initial estimate.
Frequently asked questions
What does a high ballistic coefficient mean?
A high BC means the projectile experiences less drag, retaining velocity and trajectory better over distance. It is desirable for long-range shooting.
Can I use this calculator for any projectile?
Yes, as long as you have the mass, diameter, and drag coefficient values. Remember that Cd depends on shape and velocity.
Is the ballistic coefficient the same for all velocities?
No. BC varies with velocity, especially at supersonic speeds. For accurate calculations, use a velocity-dependent BC or tabulated values.
What is the unit of the result?
The result is dimensionless but often expressed as lb/in² or just a number. The formula uses pounds and inches, so BC is in lb/in².
How do I get the drag coefficient (Cd) for my projectile?
You can find Cd values in ballistic tables for standard projectile shapes (e.g., G1, G7). Ammunition manufacturers also provide measured BCs.