About Projectile Motion with Drag Calculator
Air resistance changes a projectile's flight in ways the vacuum model cannot capture: the path becomes asymmetric, the descent is steeper and the range is shorter. For fast or light objects the difference is large enough that an ideal calculation is only a starting point.
This calculator integrates a quadratic drag model step by step, then compares the result with the analytic vacuum trajectory. You enter the launch conditions, mass and drag coefficient, and get range, flight time, maximum height, impact speed and a plot of both paths.
What this tool does
Quadratic drag model
Drag magnitude k·v² opposes velocity, so the acceleration is −g·ŷ − (k/m)·|v|·v.
Numerical integration
Fourth-order Runge–Kutta advances the flight until the projectile returns to the ground, with the landing point refined by interpolation.
Vacuum comparison
The same launch is solved analytically without drag, so range, flight time and impact speed can be compared directly.
Trajectory plot
The drag path is drawn solid and the vacuum path dashed, making the flattened descent visible.
Drag parameter explained
k is the lumped parameter ½ρC_dA, shown on the page; k = 0 switches to the vacuum case.
Editable inputs
Initial height, gravity and mass units can all be changed, so textbook values and other worlds are supported.
How to use Projectile Motion with Drag Calculator
- 01
Enter the launch conditions
Set the initial speed in m/s, the launch angle in degrees and the release height in meters.
- 02
Set gravity and mass
Keep 9.81 m/s² for Earth or change it, and enter the projectile mass in kilograms or grams.
- 03
Enter the drag coefficient k
Use k = ½ρC_dA in kg/m, or enter 0 to compare with the vacuum model.
- 04
Read the drag results
The headline gives the drag range, while the cards show flight time, maximum height, impact speed, vacuum values and the reduction percentage.
- 05
Compare the plotted paths
The solid drag curve and dashed vacuum curve show how drag flattens the flight before Reset clears the inputs.
How this tool works
- Works with
- v₀, θ, k → range
- Processing
- Client-side, in your browser. Nothing is uploaded.
- Requirements
- Chrome, Edge, Firefox or Safari · JavaScript enabled
Limitations worth knowing
- Assumes constant air density, a constant quadratic drag coefficient and no wind, spin or lift.
- Models a single plane over flat ground; vertical variation in density and curved trajectories are not included.
- The value of k is the main uncertainty, since real drag depends on speed, shape and orientation.
Privacy and file handling
Launch conditions, mass and drag coefficient are processed entirely in your browser. Nothing is uploaded, stored or logged, and the trajectory is computed locally.
Read the full privacy policy