Top of Descent Calculator
Calculate when to start your descent, required descent rate, and time to descend for a smooth, constant-angle approach.
Inputs
ft MSL
ft MSL
ft AGL
kt
°
Standard: 3°, CDFA: 3°, Visual steep: 4–5°
Results
Start Descent At
20.4 NM from destination
Required Descent Rate
637 fpm
Descent Time10.2 min
Altitude to Lose6,500 ft
Rule of Thumb (×3)20 NM
Rule of Thumb (GS×5)600 fpm
Start Descent At
20.4 NM from destination
Required Descent Rate
637 fpm
How to Use This Calculator
- Enter your cruise altitude and destination field elevation.
- Set target altitude (pattern altitude or approach altitude AGL).
- Enter your descent ground speed.
- Use 3° for standard or adjust for steep approaches.
- Begin descent at the indicated distance from the destination.
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