Speed Converter

Convert between km/h, mph, m/s, knots, Mach, and more. Instant speed conversions for driving, aviation, sports, weather, and scientific calculations.

Speed Converter

Convert between different speed units instantly. Enter a value, select the units to convert from and to, and get your conversion result.

Convert Speed

Enter the speed value you want to convert
Select the unit you're converting from
Select the unit you're converting to
Walking
Cycling
Driving
Flying
Visual representation of common speed ranges

Common Speed Conversions

Here are some of the most frequently used speed conversions across different fields:

100 km/h = 62.14 mph (Typical highway speed)
1 Mach = 767 mph (Speed of sound at sea level)
1 Knot = 1.151 mph (Nautical mile per hour)
10 m/s = 36 km/h = 22.37 mph (Sprinting speed)
Speed of light = 299,792 km/s (Scientific constant)
30 m/s = 108 km/h = 67 mph (Hurricane wind speed)
Quick Tip: To quickly convert km/h to mph, multiply by 0.621. To convert mph to km/h, multiply by 1.609. For knots to mph, multiply by 1.151.

Speed Unit Categories

Speed units are used in different contexts and fields. Here are the main categories:

Road & Land Transport

Common

Units used for vehicles, running, cycling, and general land transportation.

  • km/h - Kilometers per hour (metric countries)
  • mph - Miles per hour (US, UK)
  • m/s - Meters per second (scientific, athletics)
  • ft/s - Feet per second (US engineering)
60
mph (US Highway)
= 96.56 km/h

Aviation & Aeronautics

Specialized

Units used in aviation, aerospace, and high-speed travel.

  • Knots - Nautical miles per hour (global aviation)
  • Mach - Ratio to speed of sound (supersonic travel)
  • km/min - Kilometers per minute (spacecraft)
  • mi/min - Miles per minute (high-speed aircraft)
Mach 0.85
Typical Cruising Speed
= 567 knots = 651 mph

Maritime & Nautical

Marine

Units used for ships, boats, and maritime navigation.

  • Knots - Standard maritime speed unit
  • Nautical mph - Less common alternative
  • km/h at sea - Occasionally used

Note: 1 knot = 1 nautical mile per hour = 1.852 km/h

20
Knots (Container Ship)
= 23 mph = 37 km/h

Scientific & Extreme

Scientific

Units for scientific research, physics, and extreme speeds.

  • Speed of Light (c) - 299,792,458 m/s
  • Mach numbers - For supersonic/hypersonic speeds
  • km/s - Kilometers per second (astronomical)
  • % of light speed - Relativistic physics
17,500
mph (Orbital Speed)
= 28,164 km/h = Mach 22.9

How to Use the Speed Converter

Follow these simple steps to convert between speed units:

Step 1: Enter Speed Value

Enter the speed value you want to convert in the input field. You can use decimal numbers for precise conversions.

  • Example: 60, 100.5, 0.25
  • Positive numbers only (speed cannot be negative)
  • Scientific notation supported (e.g., 3e8 for speed of light)
Step 2: Select Units

Choose the unit you're converting from and the unit you're converting to from the dropdown menus.

  • Road km/h, mph
  • Aviation Knots, Mach
  • Scientific m/s, Speed of Light
  • Nautical Knots, nautical units
Step 3: Convert

Click the "Convert Speed" button to see your conversion result instantly. The result will show with appropriate precision.

Use the swap button to quickly reverse your conversion direction.

Use the reset button to clear values and start a new conversion.

Keyboard shortcut: Press Enter while in the input field to convert.

Step 4: Apply Results

Use your conversion results for:

  • Driving in foreign countries
  • Aviation calculations and flight planning
  • Scientific research and physics
  • Sports training and athletic performance
  • Weather forecasting and wind speeds
  • Engineering and technical specifications

Speed Conversion Examples

Here are practical examples of speed conversions for real-world scenarios:

Scenario From Unit To Unit Conversion Context
US Car in Europe 65 mph km/h 104.6 km/h US driver understanding European speed limits
Commercial Flight 550 knots km/h 1,018.6 km/h Aircraft cruising speed conversion
Olympic Sprinter 12 m/s km/h 43.2 km/h Usain Bolt's maximum speed (approx.)
Spacecraft Re-entry Mach 25 km/h 30,600 km/h Space Shuttle re-entry speed
Hurricane Winds 130 mph km/h 209.2 km/h Category 4 hurricane wind speed
Cheetah Sprint 70 mph km/h 112.7 km/h World's fastest land animal
Sound at Sea Level 767 mph Mach Mach 1.0 Reference for Mach scale
Light in Vacuum 299,792 km/s mph 670,616,629 mph Speed of light conversion
Important Note: Mach number varies with altitude and air temperature. Mach 1 at sea level (15°C) is about 767 mph, but at 35,000 ft (-55°C) it's about 663 mph.

Speed Limits Worldwide

Understanding speed limits in different countries requires unit conversion:

United States

65-85 mph

Highway speed limits vary by state. Typically 65-75 mph, with some Texas highways at 85 mph.

65 mph = 104.6 km/h
Germany (Autobahn)

Recommended 130 km/h

Many sections have no speed limit (advisory limit only). Average speeds around 130-150 km/h.

130 km/h = 80.8 mph
European Union

110-130 km/h

Most EU countries have highway limits between 110-130 km/h (68-81 mph).

120 km/h = 74.6 mph
United Kingdom

70 mph

Motorway speed limit is 70 mph (113 km/h). Uses mph despite metric system.

70 mph = 112.7 km/h
Japan

100 km/h

Expressway speed limit is typically 100 km/h (62 mph), with some sections at 120 km/h.

100 km/h = 62.1 mph
Australia

110 km/h

Maximum highway speed is 110 km/h (68 mph) in most states and territories.

110 km/h = 68.4 mph

Practical Applications

Driving & Travel

Convert speed limits and vehicle speeds when traveling between countries using different measurement systems.

Aviation & Aerospace

Convert between knots, Mach, and km/h for flight planning, aircraft specifications, and aerospace engineering.

Meteorology

Convert wind speeds between different units for weather forecasting, storm tracking, and climate research.

Sports & Athletics

Convert running speeds, cycling speeds, and athletic performance metrics for training and competition analysis.

Scientific Research

Convert velocities in physics experiments, astronomical observations, and engineering calculations.

Maritime Navigation

Convert ship speeds between knots and other units for navigation, logistics, and maritime operations.

Safety Note: Always obey local speed limits and regulations. This converter is for informational purposes only. Actual speed limits may vary by location, road conditions, and vehicle type.