Time from a Distance in Kilometres and Speed in Knots

Calculate the time it takes to travel a certain distance in kilometres based on a speed in knots. A knot is a unit of speed equal to one nautical mile per hour. The symbol used for a knot is kn or kt.

Formula

time = distance ÷ speed

Conversions

one kilometre (km) = 0.621371192237334 miles (mi)
one kilometre (km) = 0.539956803455724 nautical mile (nmi)
one knot = 1 nautical mile (nmi)
one knot (kn) = 0.514444444444444 metres per second (m/sec)
one knot (kn) = 1.68780985710119 feet per second (ft/sec)

Example Calculation

How long will it take to travel 400 kilometres at a speed of 45 knots?

First, convert the kilometres to nautical miles;

400 * 0.539956803455724 = 215.9827

Four hundred kilometres equal 215.9827 nautical miles.

Divide the distance of 215.9827 nautical miles by the speed of 45 knots to get the time in hours;

215.9827 ÷ 45 = 4.799616

It will take 4.799616 hours to travel the 400 kilometres at a speed of 45 knots.
4 hr - 47 min - 59sec