Nautical Miles and Knots Calculator
Works out how long a passage takes in knots and nautical miles, and shows the same figures in kilometres and miles.
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
The formula
time = distance ÷ speed 1 knot = 1 nautical mile per hour 1 nautical mile = 1,852 m exactly
A nautical mile is close to one minute of latitude, which is why charts use it: the side scale of a chart reads straight in miles. Current and leeway change the true speed over the ground.
What to watch out for
Use speed over the ground if you have it. A favourable or adverse tide can change passage time by more than a change of sail or throttle.
Frequently Asked Questions
How many km/h is a knot?
Exactly 1.852 km/h, or about 1.151 mph.
How long does 120 nautical miles take at 8 knots?
15 h.
How much longer is a nautical mile than a mile?
A nautical mile is 1,852 m and a land mile is 1,609 m, so it is about 15% longer.