Nautical calculations are based on the Nautical Mile (NM).
Not to be confused with:
Just like the metre, it is based on the circumference of the Planet Earth.
As such, it is allowed to keep using this unit despite the existence of SI units.
The Nautical Mile is defined as exactly 1852 m (no decimal places; this is an exact value).
It is also defined as one arc minute of a degree.
There are 60 minutes in an hour and 360 degrees in a circle.
Therefore there are 60 * 360 = 21.600 nautical miles as the circumference of the Earth.
An NM is 1852 m and therefore the circumference of the Nautical Earth is exactly
21.600 * 1852 = 40.003.200 m.
Not to be confused with:
- 'nM' = nano.Mega = 10^-9 * 10^6 = the numeric value 0,001 = milli = 'm' in prefix
- 'Nm' = Newton.metre = [default SI unit of force] * [default SI unit of distance]
- 'nm' = nanometre = 10^-9 * [default SI unit of distance]
Just like the metre, it is based on the circumference of the Planet Earth.
As such, it is allowed to keep using this unit despite the existence of SI units.
The Nautical Mile is defined as exactly 1852 m (no decimal places; this is an exact value).
It is also defined as one arc minute of a degree.
There are 60 minutes in an hour and 360 degrees in a circle.
Therefore there are 60 * 360 = 21.600 nautical miles as the circumference of the Earth.
An NM is 1852 m and therefore the circumference of the Nautical Earth is exactly
21.600 * 1852 = 40.003.200 m.