Speed Analysis Tool
Speed Calculator
Calculate speed, distance, or time using the fundamental relationship: speed = distance / time
Calculate Speed
Enter distance and time to find speed
Derived formulas:
• d = v × t (distance = speed × time)
• t = d / v (time = distance / speed)
What is Speed?
Speed is a fundamental physical quantity that measures how fast an object changes its position over time. It represents the rate of motion—the distance covered per unit of time. Whether you're walking to work, driving on a highway, or observing the motion of planets, speed quantifies the pace of movement.
As a scalar quantity, speed has magnitude but no direction. This distinguishes it from velocity, which is a vector that includes both speed and direction. When you say "I'm driving at 100 km/h," you're describing speed. When you add "heading north," you're describing velocity.
Average Speed
The total distance traveled divided by total time, regardless of speed variations during the journey. Used for trip planning and overall performance measurement.
Instantaneous Speed
The speed at a specific moment in time, shown on your car's speedometer. Represents the rate of motion at a single point during travel.
Speed calculations are essential across countless applications: transportation planning (estimating travel time), athletics (tracking performance), physics and engineering (analyzing motion), and everyday decision-making (determining when to leave for an appointment). Understanding speed helps us navigate and optimize movement in the physical world.
Common Speed Reference
Understanding speed in context: from human movement to the speed of light
Speed in Different Contexts
Speed varies dramatically depending on the context—from biological motion to astronomical phenomena. Understanding these categories helps put velocity measurements into perspective.
Land Speed
Air Speed
Water Speed
Space & Cosmic Speed
History of Speed Measurement
The concept of speed has evolved significantly throughout human history, from basic observations of motion to precise scientific measurements. Ancient civilizations had intuitive understandings of speed but lacked the tools for accurate quantification.
The development of accurate timekeeping in the 17th century, particularly pendulum clocks by Christiaan Huygens (1656), enabled the first scientific speed measurements. Galileo Galilei's experiments with rolling balls down inclined planes laid the groundwork for understanding the relationship between distance, time, and velocity.
The Industrial Revolution brought standardized units and the need for precise speed measurements in transportation. The steam engine era required engineers to calculate velocities for railway systems, leading to widespread adoption of miles per hour (mph) and kilometers per hour (km/h) as standard units.
Modern speed measurement uses sophisticated technology: radar guns measure speed through the Doppler effect, GPS systems calculate velocity from satellite positioning, and high-speed cameras capture motion at thousands of frames per second. Today, we can measure everything from the glacial movement of tectonic plates (centimeters per year) to particle velocities approaching the speed of light in accelerators.
Speed Unit Conversion Table
Quick reference for converting between common speed units. These conversion factors are precise and widely used in science and engineering.
| From / To | m/s | km/h | mph | knots |
|---|---|---|---|---|
| 1 m/s | 1 | 3.6 | 2.237 | 1.944 |
| 1 km/h | 0.278 | 1 | 0.621 | 0.540 |
| 1 mph | 0.447 | 1.609 | 1 | 0.869 |
| 1 knot | 0.514 | 1.852 | 1.151 | 1 |
Common conversions: To convert mph to km/h, multiply by 1.609. To convert km/h to mph, multiply by 0.621. For more complex conversions, use our Speed Converter tool.
Frequently Asked Questions
Common questions about speed calculations
What is the formula for speed?
The speed formula is: Speed = Distance / Time (or v = d / t). For example, if you travel 100 kilometers in 2 hours, your speed is 100 / 2 = 50 km/h.
How do I convert mph to km/h?
To convert miles per hour (mph) to kilometers per hour (km/h), multiply by 1.60934. For example: 60 mph × 1.60934 = 96.56 km/h. Use our speed converter for instant conversions.
What's the difference between speed and velocity?
Speed is a scalar quantity that measures how fast you're moving, while velocity is a vector that includes both speed and direction. This calculator measures speed only.
How accurate is this speed calculator?
Our speed calculator uses precise conversion factors and formulas to provide accurate results. It supports 9 distance units (millimeters to nautical miles) and 6 speed units for maximum flexibility.
What is average speed?
Average speed is the total distance traveled divided by the total time taken, regardless of variations in speed during the journey. It differs from instantaneous speed, which is the speed at a specific moment. For example, if you drive 200 km in 2.5 hours with varying speeds, your average speed is 200 / 2.5 = 80 km/h.
How do you calculate speed in m/s?
To calculate speed in meters per second (m/s), divide the distance in meters by the time in seconds. Formula: speed (m/s) = distance (m) / time (s). This is the SI (International System of Units) unit for speed, commonly used in physics and science.
What is the speed of sound?
The speed of sound in air at sea level and 20°C is approximately 343 m/s (1,235 km/h or 767 mph). It varies with temperature, humidity, and altitude. In water, sound travels faster at about 1,480 m/s, and in steel even faster at around 5,960 m/s.
Can I calculate running pace with this calculator?
While this calculator can compute speed, we recommend using our dedicated Running Pace Calculator for running-specific metrics like min/km, split times, and race predictions. It's optimized for runners with features like 5K, 10K, and marathon pace calculation.
What units does this calculator support?
Our calculator supports 9 distance units: millimeters (mm), centimeters (cm), meters (m), kilometers (km), inches (in), feet (ft), yards (yd), miles (mi), and nautical miles (nmi). It also supports 6 speed units: m/s, km/h, mph, knots, ft/s, and km/min.
How fast is the speed of light?
The speed of light in a vacuum is exactly 299,792,458 m/s (approximately 300,000 km/s or 186,282 miles per second). It's the fastest speed possible in the universe. Learn more with our Speed of Light Calculator.
Calculator Directory
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