Ballistic Trajectory Calculator
Calculate bullet drop, wind drift, velocity, energy and the optimum zeroing distance (OZD) for any load. Pick a bullet from our database or enter the values manually.
Choose bullet
Bullet and load parameters
Basic settings: zero, range and increment
Atmospheric conditions and wind
How this ballistic trajectory calculator works
The calculator solves the trajectory with a point-mass model: the bullet is treated as a point of mass with gravity and aerodynamic drag acting on it at every time step. Drag is read from a standard drag curve (G1 or G7) as a function of Mach number — bullet speed divided by the temperature-dependent speed of sound — and scaled by the ballistic coefficient of your bullet. Air density is derived from temperature, relative humidity and altitude and normalised against the standard atmosphere.
The solver then iterates on the launch angle until the bullet path crosses the line of sight exactly at your zero range, and samples that path at your chosen increment. From those samples come drop, wind drift, remaining velocity, energy, time of flight, the MOA corrections and the optimum zeroing distance (OZD). Spin drift, Coriolis and aerodynamic jump are not modelled — at hunting distances they stay below the dispersion of the load itself.
Getting the input values right
A trajectory calculator is only as good as its inputs. Bullet weight, diameter and BC can be taken straight from our bullet database — look your projectile up under load data by bullet or start from the cartridge under load data by caliber. Realistic muzzle velocities for a given powder and bullet combination come from our reloading load data, and for quiet loads the subsonic load data section gives usable starting figures. If you work up your own charges, keep an eye on case capacities by brass manufacturer, since they co-determine the velocity you can reach. Background on load development and measurement lives in our reloading academy blog.
Rule of thumb for priorities: a measured muzzle velocity beats the right drag model, the right drag model beats the exact BC value, and all of them beat the last decimal of temperature or humidity.
Worked example: .308 Winchester, 168 gr
A 168 gr HPBT match bullet with a G1 BC of 0.462 leaves the muzzle at 2,650 fps. Sight height is 1.7 inches, the rifle is zeroed at 100 yards, the atmosphere is 59 °F, 50 % relative humidity at sea level, and a 10 mph full-value wind comes from 3 o'clock. At 300 yards the bullet sits 14.9 inches below the line of sight, drifts about 7.5 inches sideways and still carries roughly 1,640 ft-lb. The optimum zeroing distance for this load is 181 yards, with a maximum OZD distance of 210 yards — out to there a direct hold is enough.
The tables below were pre-computed with this very solver under the conditions described. They show how much trajectories diverge once BC and muzzle velocity change.
.308 Winchester — 168 gr HPBT, G1 BC 0.462, 2,650 fps, 100 yd zero
| Distance (yd / m) | Velocity (fps / m/s) | Energy (ft-lb / J) | Drop (in / cm) | Wind drift (in / cm) | Time (s) |
|---|---|---|---|---|---|
| 0 / 0 | 2650 / 808 | 2619 / 3551 | -1.7 / -4.3 | 0.0 / 0.0 | 0.00 |
| 100 / 91 | 2457 / 749 | 2252 / 3053 | 0.0 / 0.0 | 0.8 / 2.0 | 0.12 |
| 200 / 183 | 2273 / 693 | 1926 / 2611 | -4.1 / -10.4 | 3.2 / 8.1 | 0.24 |
| 300 / 274 | 2096 / 639 | 1638 / 2221 | -14.9 / -37.8 | 7.5 / 19.1 | 0.38 |
| 400 / 366 | 1927 / 587 | 1385 / 1878 | -33.6 / -85.3 | 13.8 / 35.1 | 0.53 |
| 500 / 457 | 1768 / 539 | 1165 / 1580 | -61.7 / -156.7 | 22.5 / 57.1 | 0.69 |
OZD: 181 yd / 166 m · max height 1.6 in · max OZD distance 210 yd / 192 m
6.5 Creedmoor — 140 gr, G1 BC 0.610, 2,700 fps, 200 yd zero
| Distance (yd / m) | Velocity (fps / m/s) | Energy (ft-lb / J) | Drop (in / cm) | Wind drift (in / cm) | Time (s) |
|---|---|---|---|---|---|
| 0 / 0 | 2700 / 823 | 2266 / 3072 | -1.7 / -4.3 | 0.0 / 0.0 | 0.00 |
| 100 / 91 | 2552 / 778 | 2024 / 2744 | 1.8 / 4.6 | 0.6 / 1.5 | 0.11 |
| 200 / 183 | 2408 / 734 | 1802 / 2443 | 0.0 / 0.0 | 2.3 / 5.8 | 0.24 |
| 300 / 274 | 2269 / 692 | 1600 / 2169 | -7.8 / -19.8 | 5.3 / 13.5 | 0.36 |
| 400 / 366 | 2135 / 651 | 1416 / 1920 | -22.4 / -56.9 | 9.8 / 24.9 | 0.50 |
| 500 / 457 | 2005 / 611 | 1249 / 1693 | -44.6 / -113.3 | 15.8 / 40.1 | 0.65 |
OZD: 187 yd / 171 m · max height 1.6 in · max OZD distance 218 yd / 199 m
.223 Remington — 55 gr, G1 BC 0.243, 3,240 fps, 100 yd zero
| Distance (yd / m) | Velocity (fps / m/s) | Energy (ft-lb / J) | Drop (in / cm) | Wind drift (in / cm) | Time (s) |
|---|---|---|---|---|---|
| 0 / 0 | 3240 / 988 | 1282 / 1738 | -1.7 / -4.3 | 0.0 / 0.0 | 0.00 |
| 100 / 91 | 2830 / 863 | 978 / 1326 | 0.0 / 0.0 | 1.2 / 3.0 | 0.10 |
| 200 / 183 | 2456 / 749 | 737 / 999 | -2.7 / -6.9 | 4.9 / 12.4 | 0.21 |
| 300 / 274 | 2112 / 644 | 545 / 739 | -11.2 / -28.4 | 11.8 / 30.0 | 0.34 |
| 400 / 366 | 1797 / 548 | 394 / 534 | -27.6 / -70.1 | 22.6 / 57.4 | 0.50 |
| 500 / 457 | 1518 / 463 | 281 / 381 | -54.8 / -139.2 | 38.3 / 97.3 | 0.68 |
OZD: 205 yd / 187 m · max height 1.6 in · max OZD distance 236 yd / 216 m
The comparison makes the effect of BC tangible: the 6.5 Creedmoor starts only 50 fps faster than the .308 but still runs above 2,000 fps at 500 yards with less than half the wind drift of the .223. The .223, in turn, is the flattest of the three up close and sheds velocity fastest past 300 yards.
Explanation of the values
What is a ballistic coefficient (BC)?
The ballistic coefficient describes how well a bullet keeps its velocity against air resistance, expressed relative to a standard reference projectile. A higher BC means less deceleration, less drop and less wind drift at the same muzzle velocity. A BC is only meaningful together with the drag model it was measured against — G1 or G7.
G1 or G7 — which drag model should I choose?
G1 uses a flat-based reference projectile and fits round-nose, flat-base and most hunting bullets. G7 uses a boat-tail, secant-ogive reference shape and fits modern long-range match bullets far better, so a single G7 BC stays valid across a wide velocity band. Never mix them: a G7 BC is roughly half the numerical value of the G1 BC for the same bullet, and entering a G7 number with the G1 model will badly understate the drop.
Why does muzzle velocity matter more than BC?
Inside typical hunting distances, an error of 50 fps / 15 m/s in muzzle velocity moves the point of impact more than a 10 % error in BC. Measure the velocity of your own load over a chronograph in your own barrel rather than copying a manual figure — barrel length, throat and powder lot all shift it.
What is sight height and why does it change the trajectory?
Sight height is the distance from the centre of the bore to the centre of the optic, typically 1.5–2.0 inches / 38–50 mm on a scoped rifle. Because the bullet starts below the line of sight, it must rise to meet it. A taller mount increases the launch angle, moves the first line-of-sight crossing further out and slightly extends the optimum zeroing distance.
What is the zero range?
The zero range is the distance at which the bullet path crosses the line of sight on its way down, i.e. where point of aim and point of impact coincide. Everything the calculator reports — drop, MOA correction, wind drift — is expressed relative to that zero.
What is the optimum zeroing distance (OZD / GEE)?
The optimum zeroing distance is the zero that keeps the bullet path within a defined vertical margin — here ±4 cm / ±1.6 inches — around the line of sight for as long as possible. Up to the resulting maximum distance you can aim directly at the target without holdover and still stay inside a roe-deer-sized vital zone of about 8 cm / 3.5 inches.
What do the two line-of-sight crossings mean?
The bullet crosses the line of sight twice: once shortly after the muzzle while it is still rising (crossing 1, typically 20–35 m), and again on the descending branch (crossing 2), which is the actual zero. Between them the bullet flies above the line of sight; beyond crossing 2 it falls away increasingly fast.
How is wind drift calculated?
Wind drift comes from the crosswind component of the wind vector acting over the bullet's time of flight, so it grows faster than linearly with distance. A wind from 3 or 9 o'clock is full value; from 1, 5, 7 or 11 o'clock roughly half value; a pure head- or tailwind from 12 or 6 o'clock changes drift almost not at all and only marginally affects drop.
How do temperature, humidity and altitude affect the trajectory?
All three act through air density. Cold, dry, low-altitude air is dense and increases drag; warm air, high humidity and altitude reduce density and flatten the trajectory. Altitude dominates: moving from sea level to 2,000 m typically reduces drop at 400 m by several centimetres, while a 10 °C temperature change or the full humidity range moves it by well under one centimetre.
What does the MOA column tell me?
One minute of angle subtends about 1.047 inches at 100 yards / 2.9 cm at 100 m. The MOA columns convert drop and wind drift into the correction you dial on the turret, so a value of −4.0 MOA drop means 4 MOA of up-correction at that distance.
What energy does the calculator show?
The kinetic energy of the bullet at each distance, in ft-lb or joule depending on your unit setting. It is calculated from the remaining velocity and the bullet weight and is commonly used to check legal or ethical minimum-energy requirements for hunting at a given range.
Results are calculated with a point-mass model and are for informational purposes only. Always verify your zero and holdovers on the range.