Angle of Banking Calculator

Find how to design the perfect road (and much more) with our angle of banking calculator

Clear
Bank angle needing no friction41.381°arctan(v²/rg) — on a track banked this steeply the turn holds on a frictionless surface
Centripetal force691.2 kN80,000 kg × 8.64 m/s²
Centripetal acceleration8.64 m/s²0.881 g
Speed72 m/s259.2 km/h
Angular velocity0.12 rad/s1.146 rpm
Period of one revolution52.359878 s
Frequency0.019099 Hz
Maximum speed friction can hold68.609 m/s246.99 km/h — √(µgr), with no mass term, so a loaded and an empty vehicle corner at the same limit
Your speed against that limit104.94%over the limit — it would slide
Friction available627.6256 kNagainst 691.2 kN needed
At twice the speed2.7648 MNfour times the force — it goes as the square of speed, which is why corners punish speed so hard
At twice the radius345.6 kNhalf the force, at the same speed

The formula

a = v²/r = ω²r; F = ma

There is no centrifugal force

Circular motion needs a force pointing inward, because the velocity is constantly changing direction and that change is an acceleration towards the centre. For a car it is friction, for a satellite gravity, for a ball on a string the tension.

The outward "centrifugal force" you feel is not a force acting on you at all. It is your own inertia: your body continues straight while the car turns, and the door pushes you inward. In the rotating frame of the car it is convenient to treat that as an outward force, and doing so gives correct answers — but nothing is pulling you outward, which is why the sensation vanishes the instant the constraint does. Let go of the string and the ball flies off along a tangent, not radially outward.

The grip limit √(µgr) contains no mass, so a loaded lorry and an empty one slide at the same cornering speed — extra weight increases both the required force and the available friction in equal measure. Banking the road tilts the normal force inward so it supplies the turn directly, which is why racing circuits and railway curves are banked.