Magnetic Course Calculator
Convert a true course to a magnetic course by subtracting the magnetic variation, east positive.
Description
Convert a true course to a magnetic course by subtracting the magnetic variation, east positive.
Magnetic Course Calculator provides a focused, reproducible calculation with explicit inputs and a deterministic result. Convert a true course to a magnetic course by subtracting the magnetic variation, east positive.
Use to convert a true course with an explicitly east-positive magnetic variation and normalize the result.
When to use Magnetic Course Calculator
Use to convert a true course with an explicitly east-positive magnetic variation and normalize the result.1
How the calculation works
Convert a true course to a magnetic course by subtracting the magnetic variation, east positive.2
Magnetic course = true course − east-positive variation 1Inputs and interpretation
Keep every input on the same valuation, timing, unit, and assumption basis. Interpret the output at the precision supported by those inputs rather than treating extra decimal places as additional certainty.
Limitations and assumptions
Magnetic variation changes with place and time; charts, databases, and onboard systems must be current and use the same sign convention.
References
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Pilot's Handbook of Aeronautical Knowledge — Federal Aviation Administration
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Flight planning — Wikipedia contributors
Similar or alternative tools
- Magnetic Bearing from True Calculator
Convert a true bearing to a magnetic bearing by subtracting east-positive variation.
- True Course Calculator
Convert a magnetic course to a true course by adding the magnetic variation, east positive.
- Magnetic Heading Calculator
Convert a true heading to a magnetic heading using east-positive variation (east is least).