Physics

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Resultant Velocity Calculator.

Calculate velocity-vector magnitude from Cartesian components.

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Resultant velocity: 5 m/s

Resultant velocity

0.000000m/s

Results update automatically as you type.

Use Cases

Physics homework and exam prep

Quickly verify your manual calculations for velocity vector magnitude in kinematics problems, whether in 2D or 3D motion.

Example: Check the speed of a projectile with Vx=3 m/s, Vy=4 m/s, Vz=0 m/s → 5 m/s.

Engineering and design analysis

Determine the overall speed of an object when you know its velocity components along each axis, useful in fluid dynamics or mechanical systems.

Example: Find the resultant velocity of a drone with Vx=2, Vy=3, Vz=1 m/s.

Frequently Asked Questions

What does the Resultant Velocity Calculator do?
This calculator computes the magnitude of a velocity vector when you provide its Cartesian components (Vx, Vy, Vz) in meters per second. It uses the Pythagorean theorem in three dimensions to give you the resultant speed.
How is the resultant velocity calculated?
The resultant velocity is the square root of the sum of the squares of the components: √(Vx² + Vy² + Vz²). This gives the magnitude of the velocity vector, which is the speed in the direction of motion.
Can I use this calculator for 2D motion?
Yes, you can. If you are working in two dimensions, simply enter the Vx and Vy components and set Vz to 0. The calculator will still compute the correct resultant velocity for that plane.

Tips & Common Mistakes

Tips

  • Ensure all components are in the same unit (m/s) before entering them; the calculator assumes meters per second.
  • If you only have two components, set the third to 0 to get the correct 2D magnitude.
  • Double-check the sign of your components: negative values are allowed and will be squared, so they don't affect the magnitude.
  • Use the result as a speed value; it represents the magnitude of the velocity vector, not its direction.

Common Mistakes to Avoid

  • Forgetting to square each component before summing them – the calculator does this automatically, but manual checks often miss it.
  • Entering components in different units (e.g., km/h for one and m/s for another) without converting, leading to incorrect results.
  • Assuming the resultant velocity is simply the sum of the components – it is actually the square root of the sum of squares.

Last updated: August 13, 2026