Enter your figures
Enter the values below to calculate your result.
Global units and practical marine assumptions. Review the note beside the result for important limitations.
Calculation Results
Based on the figures you entered.
About this calculation
Convention: east variation is positive; magnetic = true − variation.
How to use this calculator
What to enter
Enter or select the following as requested: Known heading (°); Magnetic variation (°); Known heading. Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The marine result estimates a heading, distance, displacement, fuel range, runtime, or wind category from the vessel and navigation values entered. Check true versus magnetic bearings, chart datum, units, vessel loading, current, wind, and reserve assumptions.
When to use it
Use this for learning or preliminary marine planning. Verify navigation and safety-critical values against current charts, official forecasts, vessel documentation, and qualified operational procedures.