Use this calculator for flight-planning study or a first-pass cross-check when all inputs describe the same aircraft, atmospheric condition, and phase of flight.

Altitude to lose (ft)

Altitude lost during the descent.

Distance (nm)

Horizontal distance covered during the descent.

Compute the flight path angle of a descent from the altitude lost over a given distance. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Descent angle (°)

Descent flight path angle.

• Do not use a generic calculator in place of the current aircraft flight manual, approved performance data, operating limitations, NOTAMs, weather, or regulations. Real performance changes with configuration, runway condition, altitude, temperature, wind, loading, and technique.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Cross-check the result against the aircraft flight manual or approved planning system, then apply the required safety margins. Keep signed wind, heading, altitude, speed, and fuel conventions explicit.

• Approach Gradient Calculator

  Compute the approach path gradient in percent from altitude lost over nautical miles flown.

• Flight Time Calculator

  Compute the flight time over a distance at a given ground speed.

• Required Descent Gradient Calculator

  Compute the descent gradient in feet per nautical mile needed to lose an altitude over a distance.