Speed Conversion
Speed measures the rate of change of position over time, expressed as distance per unit time. It is fundamental in physics, engineering, and transportation for quantifying how fast objects move. Speed units belong mainly to metric (meters, kilometers) and imperial (miles, feet) systems, with specialized units for specific contexts like nautical or cosmic velocities. Accurate speed measurement enables navigation, safety assessments, and scientific research.
Meters per Second (m/s)
Kilometers per Hour (km/h)
Miles per Hour (mph)
Feet per Second (ft/s)
Speed of Light (c)
Speed of Sound (Mach)
Centimeters per Second (cm/s)
Millimeters per Second (mm/s)
Inches per Second (in/s)
Yards per Second (yd/s)
Kilometers per Second (km/s)
Miles per Second (mi/s)
Meters per Minute (m/min)
Kilometers per Minute (km/min)
Miles per Minute (mi/min)
Feet per Minute (ft/min)
Inches per Minute (in/min)
Yards per Minute (yd/min)
Meters per Hour (m/h)
Miles per Day (mi/d)
Kilometers per Day (km/d)
Nautical Miles per Hour (nmi/h)
Furlongs per Fortnight (fur/fn)
First Cosmic Velocity (v1)
Second Cosmic Velocity (v2)
Third Cosmic Velocity (v3)
Speed of Sound in Water (sw)
Mach (Sea Level) (Ma)
Beaufort 1 (Light Air) (Bft 1)
Beaufort 6 (Strong Breeze) (Bft 6)
Beaufort 12 (Hurricane) (Bft 12)
Leagues per Hour (lea/h)
Dekameters per Second (dam/s)
Hectometers per Second (hm/s)
Megameters per Second (Mm/s)
Gigameters per Second (Gm/s)
Terameters per Second (Tm/s)
Unit Descriptions
- Meters per Second
- The SI base unit of speed, representing meters traveled in one second.
- Kilometers per Hour
- Common metric speed unit equal to 1,000 meters per hour, used for road speeds.
- Miles per Hour
- Imperial unit measuring miles traveled in one hour, standard in the US and UK transport.
- Feet per Second
- Imperial unit denoting feet moved each second, used in engineering and ballistics.
- Knots
- Nautical speed unit equal to one nautical mile per hour, used in maritime and aviation.
- Speed of Light
- Universal constant speed in vacuum, approximately 299,792,458 meters per second.
- Speed of Sound
- Speed at which sound waves travel through air, about 343 meters per second at 20°C.
- Centimeters per Second
- Metric unit for small-scale speeds, measuring centimeters moved every second.
- Millimeters per Second
- Metric unit for very slow speeds, indicating millimeters per second.
- Inches per Second
- Imperial small-scale speed unit measuring inches traveled each second.
- Yards per Second
- Imperial speed unit representing yards moved per second, used in some sports contexts.
- Kilometers per Second
- High-speed metric unit often used in astronomy and physics.
- Miles per Second
- Imperial unit for extremely high speeds, rare outside astrophysics contexts.
- Meters per Minute
- Metric unit used for slow speeds, indicating meters traveled in one minute.
- Kilometers per Minute
- Metric unit for moderate speeds, often for industrial or rapid transport processes.
- Miles per Minute
- Imperial unit for high speeds, less common but used in some scientific measurements.
- Feet per Minute
- Imperial unit measuring feet traveled per minute, used in engineering and manufacturing.
- Inches per Minute
- Imperial slow speed unit for precision movements in machining or instrumentation.
- Yards per Minute
- Imperial speed unit indicating yards traveled each minute, used in some sports timing.
- Meters per Hour
- Metric very slow speed unit for gradual movement over an hour.
- Miles per Day
- Imperial unit measuring distance covered in miles over a full day.
- Kilometers per Day
- Metric unit showing kilometers traveled in one day, useful in long-range travel.
- Nautical Miles per Hour
- Equivalent to knots, used specifically in navigation and maritime contexts.
- Furlongs per Fortnight
- Uncommon, humorous unit combining furlongs traveled per two weeks.
- First Cosmic Velocity
- Orbital velocity around Earth, approximately 7.9 kilometers per second.
- Second Cosmic Velocity
- Escape velocity from Earth’s gravitational field, about 11.2 kilometers per second.
- Third Cosmic Velocity
- Velocity required to escape the solar system’s gravity well.
- Earth
- Average orbital speed of Earth around the Sun, roughly 29.78 kilometers per second.
- Speed of Sound in Water
- Speed at which sound waves travel in water, around 1,480 meters per second.
- Mach (Sea Level)
- Speed relative to the speed of sound at sea level, used in aerodynamics.
- Beaufort 1 (Light Air)
- Lowest Beaufort scale wind speed class, indicating light air with speeds of 1–3 knots.
- Beaufort 6 (Strong Breeze)
- Moderate wind force on Beaufort scale with speeds 22–27 knots, causing large waves.
- Beaufort 12 (Hurricane)
- Highest Beaufort scale rating, hurricane-force winds exceeding 64 knots.
- Leagues per Hour
- Traditional unit equal to three miles per hour, historically used for travel distances.
- Dekameters per Second
- Metric unit representing tens of meters traveled each second.
- Hectometers per Second
- Metric speed unit equal to hundreds of meters per second.
- Megameters per Second
- Metric unit for extremely high speeds, millions of meters per second.
- Gigameters per Second
- Unit representing billions of meters traveled per second, used in astrophysics.
- Terameters per Second
- Trillions of meters per second, a theoretical speed scale beyond physical limits.
FAQ
What is the difference between speed and velocity?
Speed is a scalar quantity representing how fast an object moves, regardless of direction. Velocity is a vector quantity that includes both speed and direction. Velocity changes if either speed or direction changes; speed alone does not consider direction.
How is speed measured in everyday life?
Speed in daily life is often measured using devices like speedometers in vehicles or radar guns for traffic enforcement. GPS systems calculate speed by measuring changes in position over time. Common units include kilometers-per-hour (km/h) and miles-per-hour (mph).
Why are knots used in maritime and aviation speed measurements?
Knots equal one nautical mile per hour and relate directly to distance on Earth’s surface, making them ideal for navigation. They simplify communication and calculations for pilots and sailors, aligning with nautical charts based on latitude and longitude.
What is the significance of the speed of light in physics?
The speed of light in vacuum (approximately 299,792,458 meters per second) is a universal constant defined by the International System of Units (SI). It sets the maximum speed for information and matter transfer, fundamental to theories of relativity and modern physics.
How does the speed of sound vary in different media?
Speed of sound depends on the medium’s density and temperature; it travels faster in solids than in liquids and gases. For example, sound moves at about 343 m/s in air at 20°C and approximately 1,480 m/s in water. These variations affect sonar technology and acoustic engineering.
What are cosmic velocities like cosmic-velocity-first, second, and third?
Cosmic velocities refer to specific escape speeds from Earth or its orbit: first cosmic velocity is orbital speed (~7.9 km/s), second is escape velocity (~11.2 km/s), and third enables leaving the solar system. These are key in aerospace engineering and space missions.
Can speed be negative?
Speed itself cannot be negative because it is a scalar quantity representing magnitude only. Negative values occur in velocity when direction is considered, indicating movement opposite to a chosen reference direction.
What is the Beaufort scale in relation to speed?
The Beaufort scale quantifies wind speed based on observed sea or land conditions, ranging from 1 (light air) to 12 (hurricane force). It provides a practical, qualitative measure used in meteorology and maritime operations.
Why are unusual units like furlongs per fortnight used?
Furlongs per fortnight is a humorous or illustrative unit combining archaic distance and time units, rarely used in practice. It highlights the need for standardized units to avoid confusion in scientific and engineering contexts.
How do units like meters-per-minute or inches-per-minute apply?
Meters-per-minute and inches-per-minute measure slower speeds often relevant in industrial processes, manufacturing, or machine calibration. They provide finer temporal resolution for low-velocity applications.