Load Factor from Bank Angle Calculator
In a level coordinated turn the wings must generate enough lift both to support the aircraft and to turn it, so the load factor (the ratio of lift to weight, expressed in G) rises with bank angle. This in turn raises the stall speed, since the wing must work harder. Enter a bank angle to find the load factor, the percentage stall speed increase, and the apparent weight multiplier. The formula is pure trigonometry and needs no aircraft-specific data.
Load factor formula
Load factor n = 1 / cos(bank angle)
Stall speed in turn = level stall speed * sqrt(n)
Stall speed increase (percent) = (sqrt(n) - 1) * 100
The effective weight multiplier equals the load factor: an aircraft and occupants feel n times their normal weight in a sustained level turn.
Load factor reference points
- 30 degrees bank: about 1.15 G, stall speed up about 7 percent.
- 45 degrees bank: about 1.41 G, stall speed up about 19 percent.
- 60 degrees bank: exactly 2.00 G, stall speed up about 41 percent.
- Normal-category certificated aircraft are limited to +3.8 G; steep turns approach this quickly.
Load factor: frequently asked questions
What is the load factor formula in a turn?
In a level coordinated turn, load factor n = 1 / cos(bank angle). At 60 degrees of bank, cos(60) = 0.5, so n = 2.0, meaning the wings must support twice the aircraft weight. The load factor does not depend on airspeed or weight, only on the bank angle.
Why does stall speed increase in a turn?
Stall speed scales with the square root of load factor. A 60 degree bank gives a load factor of 2, so the stall speed rises by the square root of 2, about 41 percent. This is why a steep turn at low speed is dangerous: the accelerated stall speed can exceed your airspeed.
What bank angle gives 2 G?
A 60 degree bank gives exactly 2 G in level flight because 1 / cos(60 degrees) = 2.0. A 30 degree bank gives about 1.15 G and a 45 degree bank gives about 1.41 G.
Does load factor depend on aircraft weight?
No. The level-turn load factor depends only on the bank angle. A light trainer and a heavy jet both pull the same number of G at the same bank angle, although the heavier aircraft experiences a larger absolute force.
Official sources
- FAA: Pilot's Handbook of Aeronautical Knowledge (load factor in turns).
- FAA: 14 CFR Part 23 (airplane flight load limits).
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.