Convert between different speed units including kilometers per hour, miles per hour, meters per second, knots, Mach number, and even relativistic speeds approaching the speed of light. Fast, accurate, and easy to use for everyday and scientific applications.
International System of Units (SI) measurements
Traditional British and American measurements
Specialized and historical measurements
Scientific and technical measurements
Input any speed value in the "From" field. Our converter accepts decimal numbers and scientific notation.
Choose your source unit (e.g., km/h) and target unit (e.g., mph) from our comprehensive unit selection.
View the converted speed in real-time. Copy results, explore common conversions, or check conversion history.
Scientific Notation Support: Our converter handles values from 10⁻¹² to 10¹⁵, making it perfect for astrophysics, quantum mechanics, and advanced engineering calculations. Input values like 1e8 for 100,000,000 or 2.5e-3 for 0.0025.
Our speed converter uses precise conversion factors and maintains accuracy up to 8 decimal places. All conversions are based on internationally recognized standards.
Yes, our converter supports negative values for applications like relative velocities, wind speeds, or scientific calculations.
Our converter can handle speeds from -1 trillion to 1 quadrillion units, covering everything from walking speed to relativistic velocities approaching the speed of light. Perfect for physics, astronomy, and advanced scientific calculations.
Enable "Show scientific notation" in preferences for very large or small values. You can also input values like 1e6 for 1,000,000.
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