Motorcycle Lean Angle Calculator
Calculate your motorcycle lean angle from corner speed and radius.
Understand the physics of cornering and your tyre's grip limits.
Lean angle is the angle between the motorcycle and the vertical, measured when cornering. Understanding lean angle helps riders appreciate the physics of cornering and the limits of tyre grip.
The physics of cornering on a motorcycle involves balancing gravity (pulling the bike down) against centrifugal force (pushing the bike outward). At equilibrium, the lean angle satisfies:
tan(θ) = v² / (g × r)
Where:
- θ = lean angle from vertical (degrees)
- v = speed (m/s)
- g = 9.81 m/s² (gravitational acceleration)
- r = corner radius (metres)
This can be rearranged as: θ = atan(v² / (g × r))
Reference lean angles:
- 15–25°: Gentle sweeping bends, confident road riding
- 30–40°: Spirited road riding, moderate corners
- 45°: Significant lean — most road tyres start at their limit here
- 50–55°: Sport riding on good surfaces with sport tyres
- 60°+: MotoGP territory — requires racing tyres, perfectly clean surfaces, and enormous skill
- Maximum theoretical: ~65° (limited by footpeg/exhaust touching down and tyre sidewall)
Tyre grip and safety margin: Road tyres typically offer a coefficient of friction of 0.8–1.0 on clean dry tarmac. The corresponding maximum lean angle is about 38–45°. Sport tyres on a track can reach 55–62°. Wet roads reduce grip by 30–50%, meaning safe lean angles drop significantly.
Important: This calculator gives the theoretical lean angle for ideal conditions. Always ride with a margin — road debris, surface changes, and mid-corner surprises require reserve grip.