Convert mph, km/h, m/s, knots, Mach, and speed of light — all conversions shown at once instantly.
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Knowledge Base
Multiply mph by 1.60934 to get km/h. For example, 60 mph × 1.60934 ≈ 96.56 km/h. To convert km/h to mph, divide by 1.60934.
Mach 1 is the speed of sound at sea level under standard atmospheric conditions, approximately 343 meters per second (1,234 km/h or 767 mph). The exact speed varies with altitude and temperature.
The speed of light in a vacuum is exactly 299,792,458 meters per second (about 299,792 km/s or 186,282 miles per second). It is denoted as c and is a fundamental constant of nature.
1 knot = 1.15078 mph or 1.852 km/h. A knot is one nautical mile per hour and is the standard unit of speed used in maritime and aviation contexts.