Speed of light to Meter per second Converter

Convert speed of light to meters per second with our free online speed converter.

Quick Answer

1 Speed of light = 299792458 meters per second

Formula: Speed of light × conversion factor = Meter per second

Use the calculator below for instant, accurate conversions.

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Last verified: December 2025|Reviewed by: Sam Mathew, Software Engineer

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Enter the value you want to convert in the 'From' field (Speed of light).
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How to Convert Speed of light to Meter per second: Step-by-Step Guide

Converting Speed of light to Meter per second involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Speed of light = 2.9979e+8 meters per second

Example Calculation:

Convert 60 speed of light: 60 × 2.9979e+8 = 1.7988e+10 meters per second

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What is a Speed of light and a Meter per second?

The speed of light in vacuum (symbol: c) is a universal physical constant that is exactly equal to 299,792,458 meters per second.

Formula: Energy (E) = Mass (m) × Speed of Light squared (c²)

Key Characteristics:

Universal Limit: It is the upper limit for the speed at which conventional matter, energy, or information can travel through space.
Constant: It is the same for all observers, regardless of their own speed or the speed of the light source (a core principle of Special Relativity).
Exact: Since 1983, it is an exact value used to define the length of the meter.

Why 'c'? The symbol 'c' stands for celeritas, the Latin word for "swiftness" or "speed."

Speed in Different Mediums

While 'c' refers to the speed in a vacuum, light slows down when passing through transparent materials:

Vacuum: 100% of c (299,792,458 m/s)
Air: ~99.97% of c (very slightly slower)
Water: ~75% of c (225,000,000 m/s)
Glass: ~66% of c (200,000,000 m/s)
Diamond: ~41% of c (124,000,000 m/s)

and Standards

The meter per second is defined as:

SI Definition

1 m/s = the velocity of a body that travels a distance of one meter in a time interval of one second.

Formula: v (m/s) = distance (m) / time (s)

SI coherence: The meter per second is a coherent derived unit, meaning it's derived directly from SI base units (meter and second) without numerical factors other than 1.

Why m/s is the "Standard"

Coherent unit integration: Physics equations work directly without conversion factors:

Force: F = ma → 1 Newton = 1 kg × 1 m/s² (acceleration in m/s²)
Momentum: p = mv → 1 kg·m/s (velocity in m/s)
Kinetic energy: KE = ½mv² → 1 Joule = 1 kg × (1 m/s)²
Power: P = Fv → 1 Watt = 1 N × 1 m/s

If you used km/h or mph, every equation would need messy conversion factors. Using m/s keeps mathematics clean and consistent across all branches of physics and engineering.

Standard Conversions

Metric conversions:

1 m/s = 3.6 km/h (exactly, since 1 hour = 3,600 seconds)
1 m/s = 0.001 km/s (kilometer per second)
1 m/s = 100 cm/s (centimeter per second)
1 m/s = 1,000 mm/s (millimeter per second)

Imperial/US conversions:

1 m/s = 3.28084 ft/s (feet per second)
1 m/s = 2.23694 mph (miles per hour)
1 m/s = 196.850 ft/min (feet per minute)

Marine/aviation:

1 m/s = 1.94384 knots (nautical miles per hour)
1 m/s = 0.00291545 Mach (at sea level, 15°C standard atmosphere)

Relationship to Acceleration

Meters per second squared (m/s²) measures acceleration (rate of change of velocity):

Gravity: g = 9.8 m/s² (velocity increases 9.8 m/s every second when falling)
Car acceleration: 0-100 km/h in 5 seconds = average 5.6 m/s² acceleration
Space shuttle launch: ~30 m/s² (3g) maximum acceleration

Note: The Speed of light is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Meter per second belongs to the metric (SI) system.

History of the Speed of light and Meter per second

Ancient to Medieval: Instantaneous or Finite?

For centuries, thinkers like Aristotle believed light was instantaneous—that it filled space immediately. Others, like Empedocles and Alhazen, argued it must have a finite speed, but it was too fast to measure with human senses.

1676: The First Measurement

Ole Rømer, a Danish astronomer, made the first quantitative estimate. He noticed that the eclipses of Jupiter's moon Io happened earlier than predicted when Earth was closer to Jupiter and later when Earth was farther away. He correctly deduced that this time difference was due to the time it took light to travel the extra distance. He estimated light took about 22 minutes to cross Earth's orbit diameter (the modern value is about 16 minutes).

19th Century: Precision on Earth

1849 (Hippolyte Fizeau): Used a rotating toothed wheel and a mirror 8 km away to measure the speed. Result: ~313,300 km/s.
1862 (Léon Foucault): Improved the method using rotating mirrors. Result: ~298,000 km/s.
1887 (Michelson-Morley): Their famous experiment attempted to detect the "luminiferous aether" (the medium light was thought to travel through). The null result proved that the speed of light is constant in all directions, regardless of Earth's motion.

20th Century: The Ultimate Standard

1905 (Albert Einstein): Published Special Relativity, postulating that the speed of light is a constant for all observers.
1972 (Evenson et al.): Used laser interferometry to measure c with incredible precision: 299,792,456.2 m/s.
1983 (The Definition): The General Conference on Weights and Measures (CGPM) decided to stop measuring c and instead define it. They fixed the speed of light at exactly 299,792,458 m/s. This effectively redefined the meter as "the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second."

and Evolution

The Metric System Birth (1790s)

French Revolution context: Pre-revolutionary France had hundreds of different units varying by region and trade, causing economic chaos and fraud. The revolutionary government sought rational, universal standards.

The meter (1793):

Defined as one ten-millionth (1/10,000,000) of the distance from the North Pole to the Equator through Paris
Physical standard: platinum bar stored in Paris
Intent: Based on Earth itself, accessible to all nations, unchanging

The second:

Already standardized internationally as 1/86,400 of a mean solar day
Based on Earth's rotation (later refined with atomic clocks)

Natural combination: Scientists and engineers naturally combined meters and seconds to express velocity, though initially various fractional units appeared (cm/s in CGS system, km/h for transportation).

19th Century: Scientific Standardization

CGS system (1860s-1870s):

Centimeter-gram-second system popular in physics
Velocity often expressed in cm/s (centimeters per second)
Used in electromagnetism, thermodynamics, fluid dynamics

MKS system (late 1800s):

Meter-kilogram-second system proposed by Giovanni Giorgi (1901)
m/s became the practical velocity unit for engineering
Better suited to human-scale measurements than cm/s

Metre Convention (1875):

Treaty of the Metre established International Bureau of Weights and Measures (BIPM)
Standardized meter and kilogram across signatory nations
Enabled consistent velocity measurements internationally—critical for:
- Ballistics and military applications
- Railway engineering (train speeds, braking distances)
- Early aeronautics and automotive engineering

SI System Adoption (1960)

11th General Conference on Weights and Measures (CGPM, 1960):

Established the International System of Units (SI)
Formally designated m/s as the coherent derived unit for velocity
Unified previously fragmented metric systems (CGS, MKS, MTS)

Coherence principle: SI units multiply and divide to form other SI units without numerical factors:

Velocity (m/s) = distance (m) / time (s)
Acceleration (m/s²) = velocity (m/s) / time (s)
Force (N = kg·m/s²) = mass (kg) × acceleration (m/s²)
Momentum (kg·m/s) = mass (kg) × velocity (m/s)

Global adoption timeline:

1960s-1970s: Scientific community worldwide adopts SI
1970s-1980s: Most countries transition official measurements to SI
1990s-2000s: International standards (ISO, IEC) require SI units
Current: ~195 countries use metric system officially; US, Liberia, Myanmar hold out for general use but use SI in science

The Speed of Light Definition (1983)

17th CGPM (1983): Redefined the meter based on the speed of light:

Speed of light in vacuum: c = 299,792,458 m/s (exactly, by definition)
The meter is now: the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second
The second is defined by atomic clocks (cesium-133 hyperfine transition)

Implications:

Fundamental constant traceability: m/s is now based on fundamental physics (speed of light), not human artifacts (meter bar)
Ultimate precision: Velocity measurements as accurate as atomic time measurements
Universal standard: Same meter per second measurement anywhere in universe

Common Uses and Applications: speed of light vs meters per second

Explore the typical applications for both Speed of light (imperial/US) and Meter per second (metric) to understand their common contexts.

Common Uses for speed of light

Astronomy and Astrophysics

Light-year: The distance light travels in one year (~9.46 trillion km).
Redshift: Measuring how fast stars move away by how their light stretches (Doppler effect for light).
Lookback Time: Using the finite speed of light to study the early universe by looking at distant galaxies.

Telecommunications

Latency: The delay in signal transmission.
Ping: The time for a signal to go to a server and back. Even at light speed, a signal to the other side of the world and back takes theoretically ~133ms minimum (in fiber), plus routing time.
Satellite Internet: Geostationary satellites are 35,786 km up. A round trip (Earth -> Satellite -> Earth) takes ~240ms, causing noticeable lag compared to fiber.

High-Energy Physics

Particle Accelerators: The Large Hadron Collider (LHC) accelerates protons to 99.9999991% of the speed of light.
Relativistic Mass: As particles approach c, they gain mass/energy rather than just speed, requiring immense energy to push them closer to the limit.

When to Use meters per second

Across Industries

Physics and Scientific Research

Fundamental constant: All velocity measurements in research papers reported in m/s
Kinematics: Position, velocity, acceleration equations use m/s and m/s²
Dynamics: Force, momentum, energy calculations require m/s for SI coherence
Relativity: Velocities expressed as fractions of c (speed of light in m/s)

Engineering

Mechanical engineering: Shaft speeds, piston velocities, fluid flow rates in m/s
Civil engineering: Wind loads, water flow in channels, traffic flow modeling
Aerospace engineering: Aircraft speeds, rocket velocities, orbital mechanics
Automotive engineering: Crash testing, braking distances, aerodynamic analysis

Meteorology and Climate Science

Wind speed: Anemometers calibrated in m/s, weather models use m/s internally
Storm classification: Hurricane/typhoon wind speeds in m/s (Saffir-Simpson scale)
Atmospheric circulation: Jet stream velocities, air mass movements
Ocean currents: Surface and deep ocean current speeds in m/s

Sports Science and Biomechanics

Performance analysis: Sprint speeds, swimming velocities, ball speeds
Equipment testing: Golf club head speed, tennis racket velocity, baseball pitch speed
Injury prevention: Impact velocities, deceleration rates during collisions
Training optimization: Treadmill speeds, cycling power-to-velocity relationships

Robotics and Automation

Motion control: Robot arm velocities, conveyor belt speeds
Autonomous vehicles: Speed sensing, collision avoidance calculations
Drones: Flight speed control, stability algorithms
Manufacturing: CNC machine tool speeds, assembly line velocities

Additional Unit Information

About Meter per second (m/s)

Why do we use m/s instead of km/h in physics?

SI coherence: The meter per second is a coherent SI unit, meaning it combines base SI units (meter, second) without numerical conversion factors. This makes physics equations work directly:

Force: F = ma where m is kg, a is m/s² → F is Newtons (kg·m/s²)
Energy: KE = ½mv² where m is kg, v is m/s → KE is Joules (kg·m²/s²)
Momentum: p = mv where m is kg, v is m/s → p is kg·m/s

If you used km/h, you'd need conversion factors in every equation:

100 km/h = 27.78 m/s
KE = ½ × 1000 kg × (100 km/h)² requires converting km/h to m/s first
Using m/s keeps math simple and consistent across all physics

How fast is 1 m/s in everyday terms?

1 m/s ≈ slow walking pace

Imagine taking one large step (about 1 meter) every second. That's 1 m/s.

Equivalents:

1 m/s = 3.6 km/h = 2.2 mph
Slower than average walking (1.4 m/s = 5 km/h)
About the pace of a leisurely stroll

Visual: If you're walking naturally and counting "one Mississippi, two Mississippi," you're covering about 1.4 meters per "Mississippi" (1.4 m/s).

What is the speed of light in m/s?

Exactly 299,792,458 m/s in vacuum (by definition)

This number is exact because the meter is actually defined based on the speed of light:

1 meter = distance light travels in 1/299,792,458 of a second
Since 1983, the meter has been defined this way

Rounded for calculations: c ≈ 3 × 10⁸ m/s (300 million m/s)

In different materials:

Air: ~299,700,000 m/s (99.97% of vacuum speed)
Water: ~225,000,000 m/s (75% of vacuum speed)
Glass: ~200,000,000 m/s (67% of vacuum speed)

How do I convert m/s to knots?

Formula: knots = m/s × 1.94384

Step-by-step example (20 m/s to knots):

20 m/s × 1.94384 = 38.9 knots
Or rough estimate: 20 × 2 = 40 knots

Quick approximation: Multiply by ~2 (actual: 1.944)

Common conversions:

10 m/s = 19.4 knots
15 m/s = 29.2 knots
20 m/s = 38.9 knots (strong wind)
25 m/s = 48.6 knots (gale force)
30 m/s = 58.3 knots (storm force)

Why knots: One knot = one nautical mile per hour, where 1 nautical mile = 1,852 meters (approximately one minute of latitude).

m/s to knots converter →

Is m/s the same as "mps"?

Yes, informally, but m/s is the correct SI symbol.

Accepted notations:

m/s (official SI symbol, most common)
m·s⁻¹ (alternative SI notation using negative exponents)
m s⁻¹ (with space, less common)
mps (informal abbreviation, spoken English, not official)

Never use:

m/sec (mix of abbreviations)
mps with periods (m.p.s.)
MPS (capital letters change meaning)

In scientific writing: Always use m/s or m·s⁻¹

In speech: "meters per second" or informally "m-p-s" (spelling out letters)

What's the difference between speed and velocity?

Speed: Magnitude only (scalar) — how fast you're moving Velocity: Magnitude + direction (vector) — how fast + which way

Example:

Speed: "The car is traveling at 30 m/s"
Velocity: "The car is traveling at 30 m/s north" or "30 m/s at 45° from the x-axis"

In physics:

Both measured in m/s
Average speed = total distance / time
Average velocity = displacement / time (can be zero if you return to start!)

Practical:

Everyday language often uses "speed" for both concepts
Physics problems require careful distinction

How fast is the speed of sound in m/s?

343 m/s at 20°C (68°F) at sea level

Temperature dependence: Speed of sound increases with temperature

0°C (32°F): 331 m/s
15°C (59°F): 340 m/s
20°C (68°F): 343 m/s
25°C (77°F): 346 m/s
Formula: v ≈ 331 + 0.6T (where T is temperature in °C)

Altitude effects:

Sea level: ~343 m/s
10,000 m altitude (jet cruise): ~299 m/s (colder air)
Stratosphere: varies widely with temperature inversions

Other materials (much faster in solids/liquids):

Water (20°C): 1,481 m/s (4.3× faster than air)
Steel: 5,960 m/s (17× faster than air)
Diamond: 12,000 m/s (35× faster than air)

Mach number: Mach 1 = speed of sound in that medium at that temperature

How do you calculate average velocity?

Formula: v_avg = Δx / Δt (displacement / time)

Where:

Δx = change in position (meters)
Δt = change in time (seconds)
Result in m/s

Example 1 (straight line):

Start: 0 m, End: 100 m, Time: 10 s
v_avg = (100 - 0) / 10 = 10 m/s

Example 2 (round trip):

Start: 0 m, travel to 100 m and back to 0 m, Time: 20 s
v_avg = (0 - 0) / 20 = 0 m/s (displacement is zero!)
Average speed = 200 m / 20 s = 10 m/s (speed uses total distance, not displacement)

What velocity do you need to reach orbit?

Low Earth Orbit (LEO): ~7,660 m/s (27,600 km/h, 17,150 mph)

Why so fast:

At this speed, centrifugal force balances gravity
You're constantly falling toward Earth but moving sideways fast enough to keep missing it
Orbit is continuous free fall

Velocity by altitude:

ISS altitude (400 km): 7,660 m/s
Geostationary orbit (35,786 km): 3,070 m/s (slower because higher orbit)
Moon's orbit: 1,022 m/s (around Earth at 384,400 km distance)

Escape velocity (leave Earth entirely): 11,200 m/s (40,320 km/h)

Challenge: Rockets must accelerate from 0 to 7,660 m/s while fighting gravity and air resistance—requires enormous energy.

How does wind speed in m/s relate to storm categories?

Beaufort Scale (wind force scale):

Calm: 0-0.5 m/s
Light air: 0.5-1.5 m/s
Light breeze: 1.5-3.3 m/s
Gentle breeze: 3.3-5.5 m/s
Moderate breeze: 5.5-8.0 m/s
Fresh breeze: 8.0-10.8 m/s
Strong breeze: 10.8-13.9 m/s
Near gale: 13.9-17.2 m/s
Gale: 17.2-20.8 m/s
Strong gale: 20.8-24.5 m/s
Storm: 24.5-28.5 m/s
Violent storm: 28.5-32.7 m/s
Hurricane: >32.7 m/s (>118 km/h, >73 mph)

Saffir-Simpson Hurricane Scale:

Category 1: 33-42 m/s (119-153 km/h, 74-95 mph)
Category 2: 43-49 m/s (154-177 km/h, 96-110 mph)
Category 3: 50-58 m/s (178-208 km/h, 111-129 mph)—major hurricane
Category 4: 58-70 m/s (209-251 km/h, 130-156 mph)
Category 5: >70 m/s (>252 km/h, >157 mph)—catastrophic

Can anything travel faster than light?

No physical object can reach or exceed the speed of light (c = 299,792,458 m/s) in vacuum.

Why (simplified):

As velocity approaches c, relativistic mass increases toward infinity
Would require infinite energy to accelerate to exactly c
Only massless particles (photons) travel at exactly c

Things that can "appear" to go faster:

Phase velocity (wave pattern speed): Can exceed c, but carries no information
Shadow/spot motion: If you sweep a laser across the Moon, the spot can move faster than c (but it's not a physical object moving)
Expansion of space: Distant galaxies recede faster than c due to space expansion, not their motion through space

Fastest things (relative to us):

Photons: c (exactly)
Neutrinos: ~c (very slightly slower, have tiny mass)
Fastest spacecraft (Parker Solar Probe): 163,000 m/s = 0.05% of c

Conversion Table: Speed of light to Meter per second

Speed of light (c)	Meter per second (m/s)
0.5	149,896,229
1	299,792,458
1.5	449,688,687
2	599,584,916
5	1,498,962,290
10	2,997,924,580
25	7,494,811,450
50	14,989,622,900
100	29,979,245,800
250	74,948,114,500
500	149,896,229,000
1,000	299,792,458,000

How do I convert Speed of light to Meter per second?

To convert Speed of light to Meter per second, enter the value in Speed of light in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our speed converter page to convert between other units in this category.

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What is the conversion factor from Speed of light to Meter per second?

The conversion factor depends on the specific relationship between Speed of light and Meter per second. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.

Can I convert Meter per second back to Speed of light?

Yes! You can easily convert Meter per second back to Speed of light by using the swap button (⇌) in the calculator above, or by visiting our Meter per second to Speed of light converter page. You can also explore other speed conversions on our category page.

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What are common uses for Speed of light and Meter per second?

Speed of light and Meter per second are both standard units used in speed measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our speed converter for more conversion options.

For more speed conversion questions, visit our FAQ page or explore our conversion guides.

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