What formula does the Climb Rate Calculator use?

The calculator uses rate of climb = (thrust minus drag) times true airspeed divided by weight. This is an excess power estimate.

Can this calculator be used for real flight planning?

No. It is for educational estimation only and must not be used for real flight planning, aircraft operation, certification, or safety decisions.

What happens if drag is greater than thrust?

If drag is greater than thrust, excess thrust is negative and the calculated climb rate becomes negative, indicating a descent estimate for the entered conditions.

Climb Rate Calculator

How the Climb Rate Calculator Works

The Climb Rate Calculator estimates the vertical speed of an aircraft using an excess power relationship. If thrust is greater than drag, the aircraft has excess thrust. Multiplying that excess thrust by true airspeed gives excess power.

Rate of Climb = Excess Power / Weight

Since excess power is:

Excess Power = (Thrust − Drag) × True Airspeed

the calculator uses:

Rate of Climb = (Thrust − Drag) × True Airspeed / Weight

Example Calculation

Thrust = 5000 N
Drag = 2000 N
True airspeed = 70 m/s
Weight = 7000 N

Excess thrust:

5000 − 2000 = 3000 N

Excess power:

3000 × 70 = 210,000 W

Rate of climb:

210,000 / 7000 = 30 m/s

What Affects Aircraft Climb Rate?

Factor	Effect on climb rate
Higher thrust	Increases excess power and climb rate.
Higher drag	Reduces excess power and climb rate.
Higher aircraft weight	Reduces climb rate for the same excess power.
Altitude and temperature	Can reduce engine power and aerodynamic performance.

Important limitation: This simplified calculator does not include propeller efficiency, engine power variation with altitude, aircraft configuration, climb speed schedule, wind, density altitude, compressibility, climb gradient requirements, or aircraft manual data.

Frequently Asked Questions

What is climb rate?

Climb rate is the vertical speed at which an aircraft gains altitude. It is commonly shown in meters per second or feet per minute.

What if the result is negative?

A negative result means drag is greater than thrust for the entered condition, giving a descent estimate instead of a climb.

Is climb rate the same as climb gradient?

No. Climb rate is vertical speed. Climb gradient is altitude gained per horizontal distance traveled.

Can this be used for real flight performance planning?

No. Use the approved aircraft flight manual, pilot operating handbook, regulations, and certified performance data.