Knots to mph
Need to convert knots to miles per hour? Multiply by 1.15078. Here is the formula and a reference chart for maritime and aviation speeds.
Formula
mph = knots × 1.15078 knots = mph × 0.868976 km/h = knots × 1.852
Quick reference chart
| From | To |
|---|---|
| 1 kt | 1.151 mph |
| 5 kt | 5.754 mph |
| 10 kt | 11.51 mph |
| 15 kt | 17.26 mph |
| 20 kt | 23.02 mph |
| 30 kt | 34.52 mph |
| 50 kt | 57.54 mph |
| 60 kt | 69.05 mph |
| 100 kt | 115.1 mph |
| 200 kt | 230.2 mph |
| 1 mph | 0.869 kt |
| 60 mph | 52.14 kt |
Why knots exist and when you need to convert them
A knot is defined as one nautical mile per hour, and a nautical mile (1,852 metres) corresponds to exactly one minute of arc of latitude on the Earth's surface. This makes navigation straightforward: if you travel at 10 knots for 60 minutes, you have moved 10 nautical miles, which maps directly to 10 arc-minutes of latitude. No additional conversion is needed when navigating by chart.
Knots are the standard speed unit in aviation and maritime contexts worldwide. Aircraft cruising speeds, ship speeds, and wind speeds in aviation forecasts are all given in knots. A commercial airliner cruises at around 450–500 knots (518–575 mph). Cargo ships cruise at 14–25 knots (16–29 mph). Wind speeds in aviation weather reports (METARs) use knots — a 20-knot crosswind is 23 mph.
For those not familiar with maritime or aviation contexts, converting knots to mph or km/h helps make the speed concrete. A fast speedboat doing 40 knots is 46 mph — roughly highway speed. A transatlantic crossing at 18 knots takes about 5.5 days from New York to Southampton, covering roughly 3,000 nautical miles (3,452 miles).
Weather forecasts for sailors and pilots frequently mix units — wind speed in knots, wave height in metres or feet, visibility in nautical miles. Converting between them quickly is a practical skill for anyone spending time at sea or in the air.
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Open Speed Converter →Frequently asked questions
How many mph is 1 knot?
1 knot equals 1.15078 miles per hour. To convert knots to mph, multiply by 1.15078.
How many knots is 30 mph?
30 mph equals 26.07 knots. Multiply 30 × 0.868976 = 26.07 knots.
Why do ships and planes use knots instead of mph or km/h?
A knot is defined as 1 nautical mile per hour. A nautical mile (1,852 metres) corresponds to 1 minute of latitude on the Earth's surface. This makes navigation calculations much simpler — distance in nautical miles equals time in hours multiplied by speed in knots.
How fast is 20 knots in mph?
20 knots equals 23.02 mph or 37.04 km/h. A typical ferry travels at 15–25 knots.
What speed is typical for planes and ships in knots?
Commercial aircraft cruise at 450–500 knots (520–575 mph). A fast ferry runs at 30–40 knots. Container ships cruise at 20–25 knots. A sailing yacht typically does 5–10 knots.
How many km/h is 1 knot?
1 knot equals exactly 1.852 km/h. This is because 1 nautical mile = 1852 metres by definition.