Ballistic Calculator

Ballistic Calculator for Trajectory, Drop, and Energy

Enter muzzle velocity, bullet weight, ballistic coefficient, zero range, wind speed, temperature, and altitude above. The tool computes the full flight path at user-defined distance intervals, returning bullet drop, wind drift, remaining velocity, retained energy, and time of flight at each step. This ballistic drop calculator accounts for aerodynamic drag, gravity, atmospheric density, and the Coriolis effect to produce predictions accurate enough for practical field use from 100 yards out to over 1,000 with appropriate input data quality.

Ballistic Coefficient and Drag Models

The ballistic coefficient (BC) describes how efficiently a bullet overcomes air resistance. Higher BC means less drag, less drop, and less wind deflection at any given distance. A streamlined boat-tail .308 match bullet (like the Sierra MatchKing 175-grain) carries a BC of roughly 0.505 on the G1 model, while a round-nose .30-30 hunting bullet might manage 0.190. At 500 yards the high-BC projectile drops about 45 inches; the low-BC bullet drops over 80. Two drag models dominate: G1 (based on a flat-base projectile shape, the traditional reference used by most manufacturers when reporting BC) and G7 (based on a boat-tail secant-ogive shape that more closely matches modern long-range bullets). A given bullet's G7 value is always numerically lower than its G1 - typically 50-55% of the G1 number. When entering data, always verify which reference model the manufacturer specifies. Using a G7 BC in a calculator expecting G1 produces severely incorrect results. This tool supports both models; select the correct one before generating your table. Those wondering how to calculate ballistic coefficient from test data: measure velocity at two known distances, then solve the drag equation for BC using the known projectile weight and caliber.

Zeroing, Sight Height, and Midrange Trajectory

A rifle "zeroed at 200 yards" means the bullet path crosses the line of sight at 200 yards. Because the scope sits 1.5-2 inches above the bore, the barrel angles slightly upward so the bullet rises above the sight line during the first half of flight, crosses it at the zero distance, and falls below it beyond. A 200-yard zero on a typical .308 load puts the bullet about 1.5 inches high at 100 yards, dead-on at 200, and approximately 8-10 inches low at 300. The maximum ordinate (highest point above the sight line) typically occurs near 55-60% of the zero distance. The calculator displays the full trajectory profile so you can pick a zero that minimizes holdover adjustments across your expected shooting distances.

Ballistic Energy Calculator and Terminal Performance

Kinetic energy (KE = ½mv²) determines how much work the bullet can do on impact. A .308 Winchester launching a 168-grain bullet at 2,650 fps carries approximately 2,620 ft-lbs at the muzzle. At 500 yards, velocity drops to roughly 1,900 fps and energy falls to about 1,345 ft-lbs. Many hunting guidelines recommend a minimum of 1,000 ft-lbs for deer-sized game and 1,500 for elk. The ballistic energy calculator output at each distance interval tells you at what range your load drops below these thresholds, defining the ethical maximum distance for a given cartridge-bullet combination. Energy alone does not determine terminal effectiveness (bullet construction, expansion, and penetration matter enormously), but it sets the floor below which reliable performance cannot be expected.

Environmental Factors: Altitude, Temperature, and Wind

Air density is the bridge between atmospheric conditions and bullet trajectory. At 5,000 feet elevation and 90°F, air is approximately 20% less dense than at sea level and 59°F (the ICAO standard atmosphere). Less dense air means less drag, which means less drop and less wind deflection at every distance. A 500-yard shot at altitude might need 2-4 inches less elevation correction than the same shot at sea level. Temperature alone has a measurable effect even at constant altitude: hot air is less dense than cold. Barometric pressure variations from weather fronts shift density by 2-3%. Of all environmental factors, wind remains the largest and least predictable variable. A 10 mph full-value crosswind at 500 yards pushes a .308 bullet roughly 15-20 inches off center. A 20 mph gust doubles that. The calculator quantifies drift for the speed you enter, but wind varies along the flight path in ways no algorithm can fully predict - reading mirage and terrain indicators at the range or in the field remains an irreplaceable marksmanship skill.

Rifle Ballistics Calculator for Common Cartridges

Popular factory loads and their approximate 100-yard-zero trajectory at 500 yards: .223 Remington 55gr at 3,240 fps drops about 52 inches. 6.5 Creedmoor 140gr at 2,710 fps drops roughly 38 inches. .308 Winchester 168gr at 2,650 fps drops about 46 inches. .300 Win Mag 190gr at 2,900 fps drops around 33 inches. .338 Lapua 250gr at 2,960 fps drops roughly 28 inches. These numbers assume sea-level standard atmosphere and vary with exact bullet BC, barrel length, and environmental conditions. Enter your specific load data above for precise predictions rather than relying on generic ballpark figures that may not match your rifle's actual performance.

Frequently asked questions