Rate of Climb

The rate of climb tells you how quickly an aircraft is gaining altitude. It is found by dividing the change in height by the time taken, so the units come out as feet per minute (fpm): if an aircraft gains more feet in the same time, its climb rate is higher. This works because it measures vertical distance covered each minute, just like speed measures horizontal distance per unit time.

Use this formula when you need to describe or compare an aircraft’s vertical performance during takeoff, approach, or a climb maneuver. It is also useful for checking whether an aircraft is climbing fast enough to clear terrain or meet a planned ascent profile.

• Using seconds instead of minutes without converting the time first
• Subtracting the altitudes in the wrong order and getting a negative climb rate
• Confusing rate of climb with groundspeed, which measures horizontal motion instead of vertical motion