Standard Turn Radius Calculator
In a level coordinated turn the horizontal component of lift provides the centripetal force that curves the flight path. From true airspeed and bank angle you can find the turn radius and the rate of turn, and you can check the bank angle needed for a standard rate (3 degrees per second) turn. This calculator uses standard gravity g = 9.80665 m/s squared and works entirely from physics, so no aircraft-specific or proprietary figures are involved.
Turn radius and rate formula
V = true airspeed in m/s (knots * 0.514444)
Radius r = V^2 / (g * tan(bank))
Rate of turn = (g * tan(bank) / V) in rad/s, converted to deg/s
Time for 360 = 360 / rate of turn
The radius result is converted to feet (1 metre = 3.28084 ft) and nautical miles (1 nm = 1,852 m). A standard rate turn is 3.00 degrees per second.
Bank angle in practice
- A common rule of thumb for standard rate bank angle is true airspeed in knots divided by 10, then add 7.
- Turn radius grows with the square of speed: doubling speed quadruples the radius at the same bank.
- Steeper bank tightens the turn but raises the load factor and stall speed.
- Always enter true airspeed, not indicated airspeed, for an accurate geometric radius.
Turn radius: frequently asked questions
What is the turn radius formula?
Turn radius r = V squared / (g * tan(bank angle)), where V is true airspeed in metres per second and g is 9.80665 m/s squared. The horizontal component of lift provides the centripetal force, so a steeper bank gives a tighter radius at the same speed.
What is a standard rate turn?
A standard rate turn (also called a rate one turn) is 3 degrees per second, completing a 360 degree turn in 2 minutes. It is the reference rate used in instrument flying. The bank angle required increases with airspeed: a common rule of thumb is bank angle in degrees equals true airspeed in knots divided by 10, plus 7.
Does turn radius depend on aircraft weight?
No. The level-turn radius formula depends only on airspeed and bank angle, not on weight, because both lift and the required centripetal force scale with mass. A heavier aircraft needs more lift but turns on the same radius at a given speed and bank angle.
Why does a faster aircraft need a steeper bank for the same rate?
Rate of turn is the angular speed. At higher true airspeed the aircraft covers more arc per second, so to keep the same 3 degrees per second it must fly a larger radius, which requires a steeper bank to generate the larger horizontal lift component.
Official sources
- FAA: Pilot's Handbook of Aeronautical Knowledge (turning flight and load factor).
- FAA: Instrument Flying Handbook (standard rate turns).
- NIST: standard acceleration of gravity, 9.80665 m/s squared.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.