Aircraft Turn Radius, Bank Angle & Load Factor Calculator
Calculate turn radius and rate of turn from true airspeed and bank angle, the load factor and stall-speed increase in the turn, the bank needed for a standard-rate turn, the 180° reversal time and the radius needed for a canyon or valley turn.
How it works
R = V² ÷ (g × tan φ); rate (°/s) = 1,091 × tan φ ÷ TAS(kt); n = 1 ÷ cos φ; Vs_turn = Vs × √n; standard-rate bank ≈ atan(3 × TAS ÷ 1,091)
In a level turn the horizontal component of lift supplies the centripetal force, so the radius depends only on true airspeed squared and the tangent of the bank angle — halving the speed quarters the radius, which is why slowing down is the first response to a valley that is closing in. The vertical component must still equal weight, so total lift and the load factor rise as 1/cos φ: 2 g at 60°, 4 g at 75.5°, and the stall speed grows with the square root of the load factor. A standard-rate turn of 3° per second, the instrument-flying norm, needs more bank the faster you fly, roughly airspeed over ten plus seven degrees. Wind does not change the turn through the air but drifts the whole circle across the ground, the reason traffic patterns and holds are corrected for it.
Worked example
At 100 kt and 30° of bank the radius is 467 m (1,533 ft), the rate 6.3°/s (a 360° in 57 s), the load factor 1.15 g and a 50 kt stall speed becomes 54 kt. Standard rate at 100 kt needs about 15° of bank; a full circle in a 15 kt wind drifts 440 m downwind.
Frequently asked questions
Why is 60° of bank a 2 g turn?
Lift must be weight ÷ cos 60° = 2 × weight. The stall speed rises by √2 = 1.41 — a 50 kt stall becomes 71 kt — which is why steep turns near the ground at approach speed are so dangerous.
Does weight change the turn radius?
Not at the same true airspeed and bank — the equation has no mass term. Heavier aircraft need a higher speed to avoid stalling, and it is the speed that enlarges the radius.
Related calculators
Planning aid using standard flight-training rules of thumb and ISA atmosphere approximations — not a substitute for the aircraft flight manual (AFM/POH) performance charts, ATC instructions or an approved flight computer. Always apply the manufacturer's data and required safety margins.