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Convert knots to miles per hour instantly with our free calculator. Essential for maritime navigation, aviation planning, sailing, weather forecasting, and understanding vessel or aircraft speeds.
1.15078
MPH per Knot
1.852 km
Nautical Mile Length
6,076 ft
Feet per Nautical Mile
Formula: MPH = Knots × 1.15078
| Knots | Miles per Hour | Context |
|---|---|---|
| 5 kt | 5.75 mph | Light sailing breeze |
| 10 kt | 11.51 mph | Moderate sailing wind |
| 15 kt | 17.26 mph | Small recreational boat |
| 20 kt | 23.02 mph | Typical sailboat cruising |
| 25 kt | 28.77 mph | Fast sailboat or ferry |
| 30 kt | 34.52 mph | Naval vessel, gale-force wind |
| 40 kt | 46.03 mph | High-speed ferry |
| 50 kt | 57.54 mph | Fast patrol boat |
| 100 kt | 115.08 mph | Small aircraft cruising |
| 150 kt | 172.62 mph | Medium aircraft |
| 200 kt | 230.16 mph | Fast turboprop aircraft |
| 300 kt | 345.23 mph | Regional jet |
| 450 kt | 517.85 mph | Commercial airliner cruise |
| 500 kt | 575.39 mph | Fast commercial jet |
| 1,000 kt | 1,150.78 mph | Supersonic aircraft |
A knot is a unit of speed equal to one nautical mile per hour. It is the standard unit for measuring velocity in maritime and aviation contexts worldwide. The term comes from the historic method sailors used to measure ship speed: they would throw a wooden board (called a chip log) attached to a rope with knots tied at regular intervals overboard, then count how many knots passed through their hands in a set time measured by a sandglass. Though this manual method has been replaced by modern instruments, the term "knot" remains the international standard for sea and air navigation.
A nautical mile is a unit of distance equal to exactly 1,852 meters (6,076 feet). This is about 15% longer than a statute mile, which is 1,609 meters (5,280 feet). The nautical mile is based on the Earth's geometry: it represents one minute of arc along any meridian (line of longitude). Since the Earth has 360 degrees of latitude and each degree is divided into 60 minutes, this means there are 21,600 nautical miles around the circumference of the Earth at the equator.
Miles per hour (mph) is the standard unit of speed used for land vehicles in the United States and a few other countries. It measures how many statute miles are covered in one hour. A statute mile is the common mile used for road distances and is exactly 5,280 feet or 1,609.344 meters.
The conversion relationship is straightforward: 1 knot = 1.15078 mph, or conversely, 1 mph = 0.868976 knots. Understanding this conversion is essential for interpreting marine weather forecasts, flight plans, vessel performance specifications, and comparing speeds across different contexts.
The formula to convert knots to miles per hour is: MPH = Knots × 1.15078. Simply multiply the speed in knots by the conversion factor 1.15078 to get the equivalent speed in miles per hour.
Question: A sailboat is traveling at 12 knots. What is its speed in mph?
This is a typical cruising speed for a mid-size recreational sailboat in moderate wind.
Question: An airliner cruises at 450 knots. Convert to mph for passenger information.
This is the typical cruising speed for a Boeing 737 or Airbus A320 at altitude.
Question: A weather forecast predicts winds of 35 knots. What is this in mph?
According to the Beaufort scale, 34-40 knots is classified as a gale, with significant sea conditions.
For a quick estimate, add 15% to the knot value or multiply by 1.15. This gives you a result within 0.07% accuracy, which is plenty for most purposes. For example: 100 knots × 1.15 = 115 mph (exact: 115.078 mph). Another trick: think of it as knots plus one-sixth more. So 60 knots = 60 + 10 = 70 mph (exact: 69.05 mph). For rough estimates, remembering that knots are about 15% slower than mph works well.
| Vessel Type | Knots | MPH |
|---|---|---|
| Rowing boat | 3-4 | 3.5-4.6 |
| Sailing dinghy | 5-8 | 5.8-9.2 |
| Canal barge | 4-6 | 4.6-6.9 |
| Fishing trawler | 10-12 | 11.5-13.8 |
| Yacht (cruising) | 6-8 | 6.9-9.2 |
| Yacht (racing) | 10-15 | 11.5-17.3 |
| Cruise ship | 20-24 | 23.0-27.6 |
| Container ship | 20-25 | 23.0-28.8 |
| Naval frigate | 28-32 | 32.2-36.8 |
| Hovercraft | 40-50 | 46.0-57.5 |
| Hydrofoil ferry | 35-50 | 40.3-57.5 |
| Aircraft Type | Knots | MPH |
|---|---|---|
| Paraglider | 15-25 | 17-29 |
| Hot air balloon | 5-10 | 6-12 |
| Cessna 172 (small plane) | 110-120 | 127-138 |
| Helicopter (light) | 100-140 | 115-161 |
| Twin-engine prop plane | 150-200 | 173-230 |
| Turboprop regional | 250-350 | 288-403 |
| Boeing 737 / A320 | 440-460 | 506-529 |
| Boeing 777 / A350 | 490-510 | 564-587 |
| Business jet | 400-500 | 460-575 |
| Military fighter (subsonic) | 400-600 | 460-690 |
| Description | Knots | MPH |
|---|---|---|
| Calm | < 1 | < 1.2 |
| Light air | 1-3 | 1.2-3.5 |
| Light breeze | 4-6 | 4.6-6.9 |
| Gentle breeze | 7-10 | 8.1-11.5 |
| Moderate breeze | 11-16 | 12.7-18.4 |
| Fresh breeze | 17-21 | 19.6-24.2 |
| Strong breeze | 22-27 | 25.3-31.1 |
| Near gale | 28-33 | 32.2-38.0 |
| Gale | 34-40 | 39.1-46.0 |
| Strong gale | 41-47 | 47.2-54.1 |
| Storm | 48-55 | 55.2-63.3 |
| Violent storm | 56-63 | 64.5-72.5 |
| Hurricane force | 64+ | 73.7+ |
All maritime charts, navigation systems, and vessel instruments use knots. Converting to mph helps land-based observers understand vessel speeds, compare with road speeds, and interpret marine weather forecasts for coastal activities.
Aircraft speeds, wind speeds at altitude, and all aviation charts use knots as the standard unit. Pilots and air traffic controllers worldwide communicate in knots for safety and standardization. Converting to mph helps passengers and ground crew understand aircraft performance.
Marine weather forecasts, tropical storm warnings, and hurricane reports use knots for wind speed. Converting to mph helps the general public understand storm severity, compare with land-based wind speeds, and make informed safety decisions.
Sailors, powerboaters, and water sports enthusiasts work with knots for speed measurement. Converting to mph allows comparison with familiar land speeds, helps newcomers understand performance, and aids in trip planning and fuel consumption estimates.
If you see 50 knots, remember it's actually about 58 mph, not 50 mph. Knots convert to a higher mph number because nautical miles are longer than statute miles.
Instead of 1.15078, use 1.15 for quick estimates. The error is less than 0.1%, which is negligible for everyday purposes. 200 knots × 1.15 = 230 mph (exact: 230.156).
30 knots is fast for a sailboat but slow for an aircraft. Always consider the context when interpreting speeds in knots or mph.
Some people mistakenly think knots and km/h are the same. They're not: 1 knot = 1.852 km/h. Always use the correct conversion factor based on which unit you're converting to.
A knot already means nautical miles per hour, so saying "knots per hour" is redundant and incorrect. Just say "knots" or "kt".
Always multiply knots by 1.15078 to get mph. Dividing would give you the wrong answer (that's the mph-to-knots conversion).
One knot equals exactly 1.15078 miles per hour. This means a vessel traveling at 1 knot covers 1.15078 statute miles in one hour. The conversion is based on the fact that one nautical mile (the distance traveled at 1 knot in one hour) equals 1.15078 statute miles.
Multiply the speed in knots by 1.15078 to get miles per hour. For example: 50 knots × 1.15078 = 57.539 mph. For a quick mental estimate, you can add about 15% to the knot value. So 100 knots is approximately 100 + 15 = 115 mph.
Knots are used in maritime and aviation navigation because nautical miles are based on the Earth's geometry. One nautical mile equals one minute of latitude (1/60th of a degree), making navigation calculations more intuitive when working with charts, coordinates, and GPS systems. This international standard ensures consistency across all countries and improves safety in communication.
A nautical mile is 1,852 meters (6,076 feet), compared to a statute mile which is 1,609 meters (5,280 feet). A nautical mile is longer than a statute mile by about 15%. The nautical mile is defined based on the Earth's circumference: it represents one minute of arc along any meridian (line of longitude).
20 knots equals approximately 23.016 mph. This is a typical cruising speed for many recreational sailboats and smaller vessels. To calculate: 20 × 1.15078 = 23.016 mph.
100 knots equals approximately 115.078 mph (or 185.2 km/h). This is a common cruise speed for small to medium-sized aircraft and represents a very fast speed for watercraft. Commercial helicopters often cruise at 120-150 knots, while small aircraft cruise at 100-180 knots.
Yes, absolutely. Meteorologists and sailors often report wind speed in knots, especially in marine weather forecasts. A gale is defined as winds of 34-40 knots (39-46 mph), while hurricane-force winds begin at 64 knots (74 mph). This converter works for any speed measurement, whether it's vessel speed, aircraft speed, or wind speed.
The term 'knot' comes from the historical method sailors used to measure ship speed. A rope with evenly spaced knots was attached to a wooden board (the chip log) and thrown overboard. Sailors counted how many knots passed through their hands in a set time (measured by a sandglass), giving them the ship's speed in 'knots.' Though technology has replaced this method, the term remains standard in maritime and aviation industries.
This calculator uses the internationally recognized conversion factor of 1 knot = 1.15078 miles per hour. For navigation, flight planning, and official maritime or aviation operations, always verify speeds with certified instruments and refer to official charts and publications. Wind speeds and vessel performance can vary based on numerous factors beyond simple speed conversion.