Speed Converter

Convert between different speed units including km/h, mph, m/s, knots, Mach, and more.

All conversions happen locally in your browser. No data is sent to servers or stored remotely.
Precision: 2Format: Decimal
Round (decimal places):
Number format:
0.62

1 km/h = 0.62 mph

🚀Quick Conversions

🏎️Common Speed Benchmarks

Walking
5 km/h = 3.1 mph = 1.4 m/s
Cycling
25 km/h = 15.5 mph = 6.9 m/s
City Speed Limit
50 km/h = 31 mph = 13.9 m/s
Highway
120 km/h = 75 mph = 33 m/s
Commercial Jet
900 km/h = 560 mph = 0.75 Mach
Speed of Sound
1235 km/h = 767 mph = Mach 1

⚙️Speed Unit Systems

SI System
Meter per second (m/s), km/h
Imperial
Mile per hour (mph), feet per second
Maritime/Aviation
Knot (nautical mile per hour), Mach
Scientific
Speed of light (c), speed of sound
Cosmic
Escape velocities (1st, 2nd, 3rd)

💡Tips

1 km/h = 0.621 mph (approximate conversion factor)

Knot = nautical mile per hour (used in maritime/aviation)

Mach number varies with altitude and temperature

Speed of light in vacuum ≈ 299,792 km/s

📊Conversion Table

Convert 1 km/h to:

Metric System

Meter per Second (m/s)
0.28
Kilometer per Second (km/s)
0
Centimeter per Second (cm/s)
27.8
Meter per Minute (m/min)
16.7
Meter per Hour (m/h)
1,000

Imperial System

Mile per Hour (mph)
0.62
Foot per Second (ft/s)
0.91
Foot per Minute (ft/min)
54.7
Mile per Second (mi/s)
0
Inch per Second (in/s)
10.9
Mile per Minute (mi/min)
0.01

Scientific

Speed of Sound (sea level) (Mach)
0
Speed of Light in Vacuum (c)
9.27e-10
First Cosmic Velocity (v₁)
3.52e-5
Second Cosmic Velocity (v₂)
2.48e-5
Third Cosmic Velocity (v₃)
1.66e-5
METRIC SYSTEM(5 units)
Meter per Second (m/s)
0.28
Kilometer per Second (km/s)
0
Centimeter per Second (cm/s)
27.8
Meter per Minute (m/min)
16.7
Meter per Hour (m/h)
1,000
IMPERIAL SYSTEM(6 units)
Mile per Hour (mph)
0.62
Foot per Second (ft/s)
0.91
Foot per Minute (ft/min)
54.7
Mile per Second (mi/s)
0
Inch per Second (in/s)
10.9
Mile per Minute (mi/min)
0.01
SCIENTIFIC(5 units)
Speed of Sound (sea level) (Mach)
0
Speed of Light in Vacuum (c)
9.27e-10
First Cosmic Velocity (v₁)
3.52e-5
Second Cosmic Velocity (v₂)
2.48e-5
Third Cosmic Velocity (v₃)
1.66e-5

What is a Speed Converter?

The Speed Converter helps you convert between km/h, mph, m/s, knots, Mach, and 19+ other speed units. Perfect for transportation, physics, athletics, and navigation applications.

Key Features:

  • 19+ Units: km/h, mph, m/s, knots, Mach, speed of light/sound
  • Multiple Systems: Metric (km/h), imperial (mph), maritime (knots), scientific
  • Quick Conversions: Common speed benchmarks instantly
  • Privacy Friendly: All calculations in your browser

Perfect For: Travelers, pilots, athletes, physicists, engineers.

Frequently Asked Questions

How do I convert km/h to mph?

To convert kilometers per hour to miles per hour, multiply by 0.621371. For example, 100 km/h = 100 × 0.621371 = 62.14 mph. To convert mph to km/h, multiply by 1.60934.

What is a knot and why is it used for ships?

A knot is one nautical mile per hour (1.852 km/h or 1.151 mph). It's used in maritime and aviation because nautical miles are based on Earth's latitude, making navigation calculations simpler on curved surfaces.

How fast is Mach 1?

Mach 1 is the speed of sound, approximately 343 m/s (1,235 km/h or 767 mph) at sea level in standard conditions. The exact speed varies with altitude and temperature because sound travels differently in different air densities.

What's the difference between m/s and km/h?

Meters per second (m/s) is the SI unit used in physics and science, while kilometers per hour (km/h) is used for everyday speeds like cars. To convert: 1 m/s = 3.6 km/h, or divide km/h by 3.6 to get m/s.

How fast is the speed of light?

The speed of light in vacuum is exactly 299,792,458 m/s (about 300,000 km/s or 186,282 miles/s). This is the universal speed limit - nothing can travel faster according to Einstein's theory of relativity.