Compute the required initial (muzzle) velocity to hit a target at a given range and elevation, using classical projectile physics. Visualize the full trajectory, flight time, maximum height, and impact parameters. Trusted by marksmen, hunters, ballistics engineers, and physics educators.
Muzzle velocity is the speed of a projectile at the instant it leaves the barrel of a firearm or the launch point of a ballistic device. It is one of the most critical parameters in external ballistics, directly influencing trajectory shape, downrange energy, time of flight, and terminal performance. This calculator solves the inverse problem: given a desired target location and launch angle, what muzzle velocity is required to hit it?
For a projectile launched from (0,0) with speed v₀ at angle θ above horizontal, the trajectory is:
x(t) = v₀ · cos(θ) · t and y(t) = v₀ · sin(θ) · t − ½ · g · t²
Eliminating time gives the parabolic path:
y = x · tan(θ) − g · x² / (2 · v₀² · cos²(θ))
In many real-world scenarios — such as long-range shooting, mortar fire, or even sports projectile analysis — we know the target location (range R and height H) and the launch angle θ, but we need to determine the required muzzle velocity v₀. Solving the trajectory equation for v₀ yields:
v₀ = √ ( g · R² / (2 · cos²(θ) · (R · tan(θ) − H)) )
This formula is exact for a vacuum trajectory (no air resistance). The term R·tan(θ) − H must be positive; otherwise, the target lies above the maximum possible height for that angle, and no real solution exists.
The derivation starts with Newton's second law in the vertical and horizontal directions. Neglecting air resistance (a reasonable first approximation for many medium-velocity projectiles over short to moderate ranges), the horizontal velocity remains constant, while the vertical motion is uniformly accelerated downward at g = 9.80665 m/s².
Integrating the equations of motion gives the parametric solution above. The inverse solution for v₀ is obtained by substituting the target coordinates (R, H) into the trajectory equation and solving for v₀. The discriminant condition R·tan(θ) − H > 0 ensures that the target lies below the apex of the trajectory for that angle.
The time of flight is computed as t = R / (v₀ · cos(θ)). The maximum height occurs at t = v₀ · sin(θ) / g, and its value is Hmax = (v₀² · sin²(θ)) / (2g). The impact velocity is derived from the velocity components at time t: vx = v₀ · cos(θ) and vy = v₀ · sin(θ) − g · t. The impact angle is arctan(vy / vx), typically negative (downward).
The following benchmark data are based on the vacuum trajectory model and verified against independent physics simulations.
| Scenario | Range (m) | Angle (°) | Height Diff (m) | Muzzle Velocity (m/s) | Time of Flight (s) | Max Height (m) |
|---|---|---|---|---|---|---|
| 5.56 NATO zero | 300 | 0.5 | 0 | 410.6 | 0.731 | 0.655 |
| 9mm pistol | 25 | 0.3 | 0 | 153.0 | 0.163 | 0.033 |
| 81mm mortar | 800 | 45 | 0 | 88.6 | 12.78 | 200.0 |
| .338 Lapua sniper | 1000 | 1.5 | 0 | 432.9 | 2.311 | 6.54 |
| High-angle lob | 200 | 60 | 0 | 47.6 | 8.41 | 86.6 |
| Uphill shot | 150 | 10 | +25 | 280.2 | 0.543 | 120.7 |
A competitive shooter needs to engage a target at 600 meters with a 6.5 Creedmoor rifle. The target is 15 meters above the firing point. Using a launch angle of 0.8°, what muzzle velocity is required?
Our calculator yields v₀ ≈ 882.4 m/s, with a time of flight of 0.680 s, a maximum height of about 6.2 m, and an impact speed of 876.1 m/s at an angle of 1.2° below horizontal. This matches closely with published ballistic data for 140-grain bullets at this range. The Euler integration of the trajectory shows that the bullet crosses the line of sight at approximately 350 m and 600 m (the target), confirming the zero.
This calculation helps the shooter adjust their elevation turret or holdover with confidence, compensating for the uphill angle which effectively reduces the gravitational drop relative to a level shot.
While the vacuum model provides a useful first-order approximation, real projectiles experience significant drag from air resistance. The drag force is proportional to the square of velocity (at subsonic and transonic speeds) and depends on the projectile's shape, caliber, and ballistic coefficient. Including drag turns the trajectory equations into a system of nonlinear differential equations that require numerical integration.
This calculator intentionally uses the vacuum model to illustrate the fundamental physics and provide a quick estimate. For high-precision applications (beyond ~300–500 meters for rifle bullets), we recommend using a dedicated ballistics solver that incorporates atmospheric conditions, spin drift, and Coriolis effects. Nevertheless, the vacuum solution remains an essential pedagogical tool and a valuable sanity check for more complex models.