Navigation Formulas
Essential formulas for IFR navigation — time, distance, wind, and corrections.
Mental arithmetic is at the heart of IFR navigation. This section gathers the essential formulas that every IFR pilot must master.
Essential Formulas
The two most commonly used categories of formulas:
Quick Reference
Fundamental Relationship
Distance = Speed × TimeIn practical aeronautical form:
Distance (NM) = Speed (kt) × Time (min) / 60Useful Conversions
| From | To | Formula |
|---|---|---|
| kt → NM/min | Gs / 60 | |
| min → seconds | min × 60 | |
| NM → km | NM × 1.852 | |
| ft → m | ft × 0.3048 |
The "1 in 60" Rule
The fundamental rule of IFR navigation:
At 60 NM from a station, 1° of angular deviation = 1 NM of lateral offset.
Applications:
- At 30 NM: 1° = 0.5 NM
- At 10 NM: 1° = 0.17 NM (≈ 1/6 NM)
- At 6 NM: 1° = 0.1 NM
This rule allows you to quickly estimate the lateral offset based on the distance from the station.