Magnus Effect (Ball Spin)

How does a free kick bend around the wall? A spinning ball drags air with it, and the resulting sideways force — the Magnus effect — curves its flight.

Magnus Effect (Ball Spin)Live

the curve of a free kick

Controls

Speed1×

Presets

Drag the green vector on the pitch to aim the launch (speed + angle), or slide the spin knob on the left rail — the curved trajectory updates live.

Spin (rev/s)

Ball speed (m/s)

Launch angle (°)

A spinning ball drags air around with it, moving faster on one side and slower on the other. The pressure difference pushes the ball sideways — the Magnus force — bending its flight. It is what curves a free kick around a wall, hooks a golf drive, and makes a curveball break. More spin means a sharper curve.

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Data Inspector

Spin30 rev/s

Directioncurves down/right

Speed25 m/s

Launch angle0°

Governing equation

F_{M} = \frac{1}{2} ρ C_{L} A v^{2} \propto ω v = 30 \times 25 = 750

Reading this result: Deflection scales with spin times forward speed, so this 30 rev/s at 25 m/s produces a gentle, gradual curve down/right.

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How it works

A spinning ball speeds the airflow on one side and slows it on the other; the pressure difference produces the Magnus force perpendicular to the motion. Topspin dives the ball, backspin lifts it, and sidespin curves it laterally. It shapes the curveball, the banana free kick, the topspin tennis forehand, and the hooked golf drive — more spin, sharper curve.

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The math, the assumptions, real-world uses, or a code translation — explained for this exact simulation.

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Frequently asked questions

Is this Magnus effect ball spin tool really free?▾

Yes. Magnus Effect (Ball Spin) runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.

Do I need to install anything?▾

No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.

Can I save or share my simulation?▾

Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.

How accurate are the results?▾

The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.