BrainyCalculators
Login
Advertisement

Speed Converter

Convert between meters per second, kilometers per hour, miles per hour, feet per second, knots, and Mach instantly. Type a value and select a unit to see all conversions at once.

Enter a value above to see all unit conversions.

Common Speed Conversions

100 km/h = 62.1 mph
60 mph = 96.6 km/h
1 knot = 1.852 km/h
Mach 1 = 1,235 km/h
1 m/s = 3.6 km/h
30 m/s = 108 km/h
1 mph = 1.609 km/h
1 ft/s = 1.097 km/h

How to Use the Speed Converter

  1. 1
    Enter a Speed Value
    Type any speed into the input field. Decimals are supported for precise conversions.
  2. 2
    Select Your Unit
    Choose the unit you are converting from — km/h, mph, m/s, knots, ft/s, or Mach.
  3. 3
    See All Conversions
    All 6 speed units update instantly. The input unit card is highlighted for reference.
  4. 4
    Switch Units Freely
    Change the source unit at any time to instantly re-convert from the new base unit.

Frequently Asked Questions

To convert kilometers per hour to miles per hour, multiply by 0.621371. For example, 100 km/h × 0.621371 = 62.1 mph. A quick mental shortcut: multiply by 0.6 for a close estimate. To go from mph to km/h, multiply by 1.60934.

To convert miles per hour to kilometers per hour, multiply by 1.60934. For example, 60 mph × 1.60934 = 96.6 km/h. Speed limits in the US are in mph, while most of the world uses km/h. 70 mph is about 113 km/h.

A knot is a unit of speed equal to one nautical mile per hour, or exactly 1.852 km/h (approximately 1.151 mph). Knots are used in maritime and aviation navigation worldwide. For example, a ship sailing at 20 knots is travelling at about 37 km/h.

The speed of sound at sea level (at 20°C) is approximately 343 meters per second, or about 1,235 km/h (767 mph). This is Mach 1. The speed of sound varies with temperature and altitude — at 35,000 feet altitude it drops to about 1,062 km/h. Aircraft that exceed Mach 1 are said to be supersonic.

Mach 2 is twice the speed of sound — approximately 2,470 km/h (1,535 mph) at sea level. Modern fighter jets such as the F-15 and MiG-25 can reach Mach 2+. The Concorde cruised at about Mach 2 (2,179 km/h). The SR-71 Blackbird holds the air-breathing aircraft speed record at over Mach 3.

Related Calculators

📏 Conversion

Length Converter

Convert between all length and distance units: meters, feet, inches, miles, kilometers, centimeters, and more.

Calculate now
🌡️ Conversion

Temperature Converter

Convert between Celsius, Fahrenheit, Kelvin, and Rankine temperature scales instantly.

Calculate now
⚖️ Conversion

Weight Converter

Convert between weight and mass units: kilograms, pounds, grams, ounces, tons, and more.

Calculate now