Nautical Converter

Nautical units are used in maritime and aviation navigation.

Distance conversions:

• 1 nautical mile = 1.852 km (exact, by international agreement)
• 1 nautical mile = 1.15078 statute miles
• 1 nautical mile = 6,076.12 feet
• 1 nautical mile = 1 minute of latitude (by definition)

Speed conversions:

• 1 knot = 1 nautical mile per hour
• 1 knot = 1.852 km/h (exact)
• 1 knot = 1.15078 mph
• 1 knot = 0.51444 m/s

Common references:

• Cruise ship: 20-24 knots (37-44 km/h)
• Container ship: 14-24 knots (26-44 km/h)
• Commercial aircraft: 450-550 knots (833-1,019 km/h)
• Sailboat: 5-8 knots (9-15 km/h)

Why nautical miles? They relate directly to Earth’s geometry. 1 nautical mile = 1 arc minute of latitude. This makes navigation calculations much simpler.

Because of that, 60 nautical miles equals one degree of latitude, and a navigator can step off distance against the latitude scale on the edge of a chart with no conversion at all. No land-based mile has that property, which is why ships and aircraft never gave it up.

A nautical mile runs about 15 percent longer than the statute (land) mile, so the two aren’t interchangeable, and a speed in knots is faster than the same number in mph. The word “knot” itself is a leftover from how speed was once measured: sailors trailed a rope with knots tied at fixed intervals and counted how many slipped overboard in a set time. The unit kept the name long after the rope disappeared.