Quick Start
Enter bullet specifications, environmental conditions, and target parameters. Click "Calculate Trajectory" to generate ballistic data.
Bullet Parameters
Weight (grains): Bullet weight in grains. Typical: .223 (55-77 gr), .308 (150-180 gr), .30-06 (150-220 gr).
Diameter (inches): Bullet caliber. Common: .224" (.223), .264" (6.5mm), .308" (.308/.30-06). Not used in trajectory calculations.
Length (inches): Bullet length. Measure from tip to base. Not used in trajectory calculations.
BC (Ballistic Coefficient): Drag efficiency relative to standard projectile. Range: 0.1-0.8. Higher = better aerodynamics.
Drag Model: G1 (traditional) vs G7 (modern). G7 more accurate for boat tail bullets, G1 for flat base bullets.
Shooting Parameters
MV (Muzzle Velocity): Initial bullet velocity in fps. Critical for trajectory calculation. Typical: .223 (3000+ fps), .308 (2600-2800 fps).
Zero Range: Distance where bullet hits crosshairs. Common: 100, 200, 300 yards. Affects trajectory shape.
Scope Height: Distance from bore centerline to scope centerline. Typical: 1.5-2.5 inches. Affects trajectory calculation.
Environmental Conditions
Temperature: Air temperature in Fahrenheit. Affects air density - higher temperature = less dense air. Standard: 59°F.
Humidity: Relative humidity percentage. Minimal effect on ballistics. Typical: 20-80%.
Altitude: Height above sea level in feet. Higher altitude = less air resistance. Sea level: 0 ft, high altitude: 5000+ ft.
Wind Conditions
Wind Speed: Wind velocity in mph. Always positive value.
Wind Direction: Wind direction using 12-hour clock (1-12). 12 = tailwind, 3 = from right, 6 = headwind, 9 = from left.
Trajectory Parameters
Max Range: Maximum distance for trajectory calculation.
Step Size: Distance between trajectory points. Smaller steps = more detailed data. Typical: 25-100 yards.
Angle Units: Units for drop and drift display. MOA (Minutes of Angle) or mrad (milliradians).
Results
Range: Distance in yards from muzzle.
Drop: Vertical bullet drop from line of sight. Positive = below crosshairs, negative = above crosshairs.
Drift: Horizontal wind deflection.
Velocity: Bullet speed at that range. Decreases due to air resistance.
Energy: Kinetic energy in foot-pounds. Decreases with velocity.
Time: Flight time from muzzle to that range.
Technical Tips
Data Sources: Use manufacturer BC values from ballistic tables. Measure MV with chronograph for accuracy.
Environmental Matching: Set conditions to match your shooting environment for accurate results.
Wind Reading: Wind direction and speed can change rapidly. Use average conditions for planning.