Switch Tool
Everyday Essentials
Engineering & Data
13 tools — all free & precise
Speed
Speed Converter
Convert km/h, mph, knots, m/s, and more
Conversion Formula
Target = Value × (From Ratio / To Ratio)
Speed conversions use linear ratios. Target = Value × (Source Ratio / Target Ratio). To convert km/h to mph: multiply by 0.277778 / 0.44704.
Speed conversion is useful in driving, aviation, sailing, and sports. Convert between km/h, mph, knots, m/s, and ft/s.
Knots are used in aviation and maritime contexts. One knot equals one nautical mile per hour (1.852 km/h).
All Supported Speed Units
| Unit | Symbol | Definition |
|---|---|---|
| Meter per second | m/s | The SI unit of speed, meters traveled per second. |
| Kilometer per hour | km/h | Kilometers traveled per hour, the standard road speed unit worldwide. |
| Mile per hour | mph | Miles traveled per hour, the road speed unit in the US and UK. |
| Knot | kn | One nautical mile per hour, used in aviation and maritime navigation. |
| Foot per second | ft/s | Feet traveled per second, used in engineering and physics. |
| Inch per second | in/s | Inches traveled per second, used in precision machinery. |
| Mach (Speed of Sound) | Ma | The ratio of speed to the speed of sound in air at sea level. |
Common Speed Conversions
| From | To | Value |
|---|---|---|
| 1 km/h | mph | 0.621 |
| 1 mph | km/h | 1.609 |
| 1 knot | km/h | 1.852 |
| 1 m/s | km/h | 3.6 |
Frequently Asked Questions
To convert kilometers per hour to miles per hour, multiply by 0.6214. For example, 100 km/h × 0.6214 = 62.14 mph. This is essential for international driving.
A knot is one nautical mile per hour. One knot = 1.15078 mph = 1.852 km/h. Knots are used in aviation and maritime navigation worldwide.
To convert meters per second to kilometers per hour, multiply by 3.6. For example, 10 m/s × 3.6 = 36 km/h. This is commonly used in physics and sports.
Mach number is the ratio of an object's speed to the speed of sound in the surrounding medium. Mach 1 equals approximately 343 m/s or 1,235 km/h at sea level.
One knot equals approximately 1.15078 miles per hour. To convert knots to mph, multiply by 1.151. For example, 20 knots ≈ 23 mph.
To convert miles per hour to kilometers per hour, multiply by 1.60934. For example, 60 mph × 1.609 = 96.56 km/h. This is useful for US drivers traveling abroad.
The speed of sound at sea level is approximately 1,235 km/h (767 mph) at 20°C. This varies with temperature, altitude, and atmospheric conditions.