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E6B learning calculator
Solve a steady-wind cruise exercise using true directions, nautical miles, knots and litres. Change one input at a time to see which assumption changes the result.
Your cruise exercise
- True heading
- 90.0°
- Wind correction
- +0.0°
- Groundspeed
- 100.0 kt
- Cruise time
- 72.0 min
- Cruise fuel
- 36.0 L
Show the working
Time = 120 NM ÷ 100.0 kt = 1.200 hours.
Cruise fuel = 1.200 h × 30 L/h = 36.0 litres.
Positive correction turns the heading to the right of the true course. True heading is not a magnetic compass heading.
Why these results change
The calculator resolves wind into components along and across your course. The crosswind component changes heading; the component along the course changes groundspeed. The wind-correction angle is asin(wind speed × sin(wind-from direction − course) ÷ true airspeed). Groundspeed is true airspeed × cos(correction) − wind speed × cos(wind-from direction − course).
Compare the worked example
| Wind | Groundspeed | Cruise time | Cruise fuel |
|---|---|---|---|
| Calm | 100 kt | 72 min | 36 L |
| From 090° at 20 kt | 80 kt | 90 min | 45 L |
The headwind adds 18 minutes and nine litres to this invented cruise exercise. Read the complete fuel-planning lesson to understand why cruise fuel alone is not the total fuel required.
Model assumptions and sources
Wind, airspeed and burn are constant. Directions use degrees true; the wind direction is where the wind comes from. Inputs are not retrieved from a live weather service or aircraft database. The calculation cannot determine weather suitability, aircraft capability or a legal reserve. Use the FAA aviation handbooks and the CAA Skyway Code for the wider planning context.
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