Convert m/s to km/h metres per second ↔ kilometres per hour Free Online Secure
Type a value in metres per second and read it in kilometres per hour at once. The factor is exact by definition, the arithmetic happens in your browser, and nothing is sent anywhere.
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Convert from metres per second
Convert to kilometres per hour
Common values — Convert m/s to km/h (metres per second ↔ kilometres per hour)
| m/s | km/h |
|---|---|
| 1 | 3.6 |
| 2 | 7.2 |
| 3 | 10.8 |
| 5 | 18 |
| 10 | 36 |
| 20 | 72 |
| 50 | 180 |
| 100 | 360 |
Where these units come from
Speed has no unit of its own: it is a length divided by a time, so every trade simply kept the length it was already using. That is why the same motion is 100 km/h on a European road sign, 62 mph on an American one and 27.8 m/s in a physics problem. The knot is the oldest of them and the most literal: sailors paid out a line with knots tied at even spacing and counted how many ran through their fingers while a sand glass emptied, so the speed was read off in knots. One knot is one nautical mile per hour, and a nautical mile is a minute of latitude — which is why ships and aircraft still use it. The speed of light is the odd one out: since 1983 it is not measured but fixed at exactly 299,792,458 m/s, because the metre is now defined from it.
Where you meet them
Kilometres and miles per hour live on speedometers and road signs, metres per second in physics, engineering and wind reports, feet per second in ballistics and in American machine shops. Knots carry shipping, aviation and marine weather, and Mach numbers appear wherever an aircraft is fast enough for the air's own stiffness to matter. The speed of light turns up less in daily life than in distances: a light year is simply how far it gets in one.
Questions people ask
Is Mach 1 a fixed speed?
No. Mach is a ratio to the speed of sound in the surrounding air, and sound travels more slowly in colder air. This page uses the standard sea-level figure, 340.294 m/s, so Mach 1 here is about 1225 km/h. At the altitude airliners cruise at, the air is some 50 degrees colder and the same Mach 1 is roughly a tenth slower. An aircraft can therefore hold a constant Mach number while its speed over the ground changes.
Why do ships and aircraft use knots rather than km/h?
Because a nautical mile is one minute of arc of latitude. A vessel making one knot covers one minute of latitude in an hour, so speed, time and position on a chart fit together without conversion. The same reasoning kept the nautical mile at exactly 1852 metres rather than rounding it to something tidier.
Is the answer exact?
Where both units are defined in terms of one another by whole numbers, yes — the page says so above the figure, and the only rounding is in how many digits are shown. Where the ratio has no finite decimal, the page shows twelve significant digits and says the relation is approximate rather than pretending otherwise.
Does anything I type leave my device?
No. The arithmetic runs in your browser; nothing is uploaded and there is no server to upload it to. Load the page once and it keeps working with the network switched off.
Sprinters, cheetahs and peregrine falcons: from m/s to km/h
A sprinter who runs the 100 metres in under ten seconds averages more than ten metres per second. A cheetah chasing a gazelle may reach nearly thirty. A peregrine falcon in a stoop is faster still. Sports scientists and biologists measure speed in metres per second because the physics works in SI units, while commentators, coaches and fans think in kilometres per hour. To convert m/s to km/h, multiply by 3.6: 10 m/s is 36 km/h, 25 m/s is 90 km/h and 29 m/s is 104.4 km/h. The calculator above multiplies as you type, and the sections below show what the figures mean for athletes, animals and machines.
You will find the rule with worked examples, a short profile of each unit, a comparison, a long set of cases from sport and nature and the slips to avoid. The arithmetic runs in your browser, and what you type is not sent anywhere.
How to convert m/s to km/h: multiply by 3.6
The rule
One metre per second covers 3,600 metres in an hour, which is 3.6 kilometres. To convert m/s to km/h, multiply the metres per second by 3.6. So 5 m/s is 18 km/h, 12 m/s is 43.2 km/h and 30 m/s is 108 km/h. To go the other way, divide by 3.6.
Worked examples
A brisk walk of 1.4 m/s is 5.04 km/h. A cyclist at 12 m/s is going 43.2 km/h. A thoroughbred galloping at 17.5 m/s is at 63 km/h, and a tennis serve at 73 m/s is at 262.8 km/h.
Why 3.6
An hour has 3,600 seconds and a kilometre has 1,000 metres. The ratio of 3,600 to 1,000 is 3.6. The factor is exact, so no rounding enters the conversion.
A quick sanity test
The figure in km/h is always 3.6 times the figure in m/s. If a “convert m/s to km/h” calculation result is smaller than the starting number, you divided instead of multiplying.
The metre per second
The SI unit of speed
The metre per second is the SI unit of speed. Physicists, sports scientists and biologists use it because it combines directly with metres, seconds and newtons. In timing, speed is calculated from distance and time, which gives m/s naturally.
Where it appears
Biomechanics papers, track and field analysis, physics lessons and engineering data.
The kilometre per hour
The unit of everyday speed
The kilometre per hour is how drivers, runners, cyclists and commentators describe speed. It gives numbers of a convenient size for road traffic and for most sports, which is why broadcasts and news reports prefer it.
Where it appears
Speed limits, sports broadcasts, bicycle computers and news reports.
Metres per second against kilometres per hour
One m/s equals 3.6 km/h, so a figure in km/h is always bigger. A sprinter at 10 m/s sounds slower than the same athlete at 36 km/h, though they are the same. Track coaches use m/s for analysis and km/h for speaking to the public, so a “convert m/s to km/h” calculation often sits between a lab report and a news story about the same race.
The factor is exact, with no rounding. The only trap is direction: from m/s to km/h the number grows.
Where the conversion shows up
Sprinting
Usain Bolt's 100 m record of 9.58 seconds is an average of 10.44 m/s, which is 37.6 km/h. His peak speed between 60 and 80 metres was about 12.4 m/s, which is 44.7 km/h. A marathon world record near two hours is an average of about 5.83 m/s, or 21 km/h. A “convert m/s to km/h” calculation makes the sprint and the marathon comparable at a glance.
Land animals
A cheetah reaches up to about 29 m/s, or 104 km/h, in short bursts. A pronghorn antelope sustains 25 m/s, or 90 km/h, over long distances. A greyhound runs near 18 m/s, or 65 km/h, a thoroughbred 17.5 m/s, or 63 km/h, and an elephant at full charge about 11 m/s, or 40 km/h. A human walking is at 1.4 m/s, which is 5 km/h.
Flight and falling
A peregrine falcon in a steep dive has been recorded at more than 80 m/s, which is above 288 km/h. A skydiver in free fall belly-down reaches about 55 m/s, or 198 km/h, and about 85 m/s, or 306 km/h, in a head-down position. A hummingbird's courtship dive reaches roughly 27 m/s, or 97 km/h.
Cycling
A fit amateur on a flat road rides at 7 m/s, which is 25 km/h. Tour de France riders in a flat stage average 11 to 12 m/s, which is 40 to 43 km/h, and sprinters in the final reach 20 m/s, or 72 km/h. The one-hour record, set on a velodrome, is about 56 km/h, which is 15.6 m/s. Bicycle computers show km/h, while wind-tunnel analyses are done in m/s.
Animal migration
Migrating birds cruise at 10 to 20 m/s, which is 36 to 72 km/h. A bar-tailed godwit flew about 11,000 km without stopping in roughly 11 days, an average of about 11.6 m/s, or 42 km/h. Whales swim at 1 to 3 m/s, or 3.6 to 11 km/h, over thousands of kilometres. Researchers who track animals by satellite log m/s and publish km/h.
Insects and small flyers
A honeybee flies at 7 m/s, which is 25 km/h, and a dragonfly at up to 10 m/s, or 36 km/h. A housefly manages about 2 m/s, or 7 km/h. Insects are small, so their speeds in body lengths per second are impressive even when the absolute numbers are modest. Entomologists use m/s in papers and km/h in outreach.
Thrown and launched objects
A javelin leaves the hand at about 30 m/s, which is 108 km/h. A shot put goes out at 14 m/s, or 50 km/h, and a golf drive at 75 m/s, or 270 km/h. These speeds determine how far each object travels, since range grows with the square of the launch speed. A doubling of speed means four times the distance.
Machines in the gym
A treadmill set to 12 km/h runs at 3.33 m/s. A rowing machine displays the split time per 500 metres, and 2:00 per 500 m is 4.17 m/s, which is 15 km/h. Cycling trainers show watts and km/h. Equipment makers store speed in m/s internally and convert for display with a “convert m/s to km/h” calculation.
Reaction and safety distances
A driver with a reaction time of 1 second travels 14 metres at 50 km/h, which is 13.9 m/s, and 28 metres at 100 km/h, which is 27.8 m/s. Safety standards for playground surfaces and helmets use impact speeds in m/s, such as 5 m/s, which is 18 km/h, a typical bicycle fall. Converting makes the figures vivid for parents.
Spreadsheet formulas
Put speeds in m/s in column A and use =A2*3.6 in column B. For the reverse, use =B2/3.6. Add a column for pace, =1000/A2/60, to give minutes per kilometre. Label every column with its unit, and use one decimal for km/h.
Rounding and precision
The factor is exact, but measurements are not. A time of 9.58 seconds is given to the hundredth, so 10.44 m/s is honest, while 37.58 km/h suggests more precision than a typical broadcast offers. Round km/h to one decimal in articles, and to whole numbers when the speed is in a headline.
A mental shortcut
Multiply by 4 and take off 10 per cent. For 10 m/s: 40 minus 4 gives 36 km/h. For 25 m/s: 100 minus 10 gives 90 km/h. For 7 m/s: 28 minus 2.8 gives 25.2 km/h. The shortcut is exact because 4 minus 0.4 is 3.6.
Landmarks to memorise
1.4 m/s is a walk at 5 km/h, 3 m/s is a jog at 10.8 km/h, 6 m/s is a fast run at 21.6 km/h, 10 m/s is a sprint at 36 km/h, 25 m/s is a pronghorn at 90 km/h and 50 m/s is a falcon in a dive at 180 km/h. These landmarks help you judge any speed.
Reference ladder
0.5 m/s is 1.8 km/h. 2 m/s is 7.2 km/h. 5 m/s is 18 km/h. 8 m/s is 28.8 km/h. 12 m/s is 43.2 km/h. 20 m/s is 72 km/h. 30 m/s is 108 km/h. 50 m/s is 180 km/h. 100 m/s is 360 km/h. A ladder like this makes proofreading a draft faster.
Swimming and rowing
A top swimmer in a 100 m freestyle averages just over 2 m/s, about 7.7 km/h, which looks slow beside a runner. An eight-person rowing crew over 2,000 m in six minutes averages 5.6 m/s, or 20 km/h. Water is dense, so speeds in the pool and on the lake are far lower than on land. Coaches track m/s and publish km/h for the public.
Checking by reversing
To check any convert m/s to km/h result, divide it by 3.6. If 25 m/s became 90 km/h, then 90 divided by 3.6 is 25. A second test is the size: the km/h figure should be a little under four times the m/s figure.
Relation to mph
One m/s is 2.237 mph. A sprinter at 10.44 m/s is at 23.4 mph, a cheetah at 29 m/s is at 64.9 mph and a tennis serve at 73 m/s is at 163 mph. American broadcasts show mph, European ones km/h, and scientists m/s, so the same event is described three ways.
Speed in body lengths
Biologists sometimes compare speeds by body length per second. A cheetah, 1.2 m long, at 29 m/s covers about 24 body lengths each second. A tiny mite of 0.5 mm running at 0.1 m/s covers 200 body lengths per second, relatively faster than any large animal. The absolute speed in km/h hides this.
Kinetic energy
Kinetic energy grows with the square of speed. A 80 kg sprinter at 10 m/s has 4,000 joules; at 5 m/s only 1,000. A 1,500 kg car at 27.8 m/s, which is 100 km/h, has about 579,000 joules. A “convert m/s to km/h” calculation gives a feel for the speed, while the square law gives a feel for the danger.
Timing gates and radar
Sports timing uses gates that measure the interval between two beams. With a gate spacing of 10 m and an interval of 0.9 s, the speed is 11.1 m/s, which is 40 km/h. Radar guns measure Doppler shift and display km/h or mph. Laboratory systems log m/s, and a conversion routine supplies the display units.
Paralympic and wheelchair racing
Elite wheelchair racers reach 9 to 10 m/s over a track, which is 32 to 36 km/h, and more than 12 m/s, or 43 km/h, on a long downhill road. Handcycle racers exceed 20 m/s, or 72 km/h, on descents. Classification and timing use m/s in technical papers, and a “convert m/s to km/h” calculation helps spectators compare the speeds with those of runners and cyclists.
Horse racing and the furlong
A race over a furlong, 201 metres, run in 10 seconds has an average of 20.1 m/s, which is 72.4 km/h, a figure a thoroughbred achieves only briefly. Over a mile in 1 minute 36 seconds, the average is 16.8 m/s, or 60.3 km/h. Racing charts list fractions of a second per furlong, and analysts convert to m/s or km/h to compare tracks across countries.
Winter sports
Alpine downhill racers reach 40 m/s, or 144 km/h, and the speed-skiing record is over 70 m/s, which is about 255 km/h. Bobsleds and luge sliders run near 40 m/s, which is 144 km/h. Elite speed skaters hold about 15 m/s, or 54 km/h, for lap after lap. A “convert m/s to km/h” calculation puts these figures on the same page as a car on the motorway.
Ball sports
A fastball of 105 miles per hour is 47.3 m/s, or 170 km/h. The fastest recorded tennis serve is around 263 km/h, which is 73 m/s. A hard football kick leaves the boot at about 35 m/s, or 126 km/h, and a cricket fast bowler delivers at 40 m/s, or 144 km/h. Radar guns display one unit, and the broadcast graphic may show another.
Motor racing
A Formula One car on a long straight reaches 90 m/s, or 324 km/h. A rally car on gravel sustains 40 m/s, or 144 km/h. Engineers in the pit use m/s for aerodynamic calculations, while the dashboard and the commentators use km/h. The ratio of 3.6 lets a lap-time analyst move between them without a calculator.
Slow movers
A garden snail crawls at about 0.001 m/s, which is 3.6 metres per hour. An ant runs at 0.01 m/s, or 0.036 km/h, and a giant tortoise at 0.07 m/s, or 0.25 km/h. In m/s the numbers are small and awkward, which is why biologists often switch to centimetres per second or metres per minute for slow creatures.
Athletics wind limits
Record-eligible sprint times require a tailwind of no more than 2.0 m/s, which is 7.2 km/h. A tailwind of 5 m/s, or 18 km/h, would speed up a 100 m race by about a tenth of a second or more. The rule is stated in m/s because anemometers beside the track read in that unit.
Runners and pace
Runners think in minutes per kilometre. A pace of 5 minutes per kilometre is 3.33 m/s, or 12 km/h. A 4-minute kilometre pace is 4.17 m/s, or 15 km/h. Treadmills show km/h while sports watches show pace, and a “convert m/s to km/h” calculation links the lab measurement to the treadmill setting.
Human limits
The fastest recorded human sprint speed is just over 12 m/s, about 44.7 km/h. A trained athlete sustains 10 m/s for about 10 seconds. Biomechanists study how stride length and frequency combine to give this speed: for example, 4.6 strides per second at 2.6 metres each gives 12 m/s. The data come in m/s and the headlines in km/h.
More values for convert m/s to km/h
A longer list of conversions
If the value you need is not in the first list, these further conversions may be close enough to read off directly:
- 0.1 m/s = 0.36 km/h
- 0.5 m/s = 1.8 km/h
- 3 m/s = 10.8 km/h
- 4 m/s = 14.4 km/h
- 7 m/s = 25.2 km/h
- 15 m/s = 54 km/h
- 20 m/s = 72 km/h
- 75 m/s = 270 km/h
- 200 m/s = 720 km/h
- 500 m/s = 1,800 km/h
- 2,000 m/s = 7,200 km/h
- 10,000 m/s = 36,000 km/h
Common slips when you convert m/s to km/h
Dividing instead of multiplying
From m/s to km/h the number grows. If 25 m/s became 6.9, you divided.
Using 1.6
1.609 is the factor between miles and kilometres. Between m/s and km/h the factor is 3.6.
Confusing average and peak speed
An average of 10.44 m/s over 100 m is not the top speed. Peak speed is higher, so use the right figure for the claim.
Short answers
How do I convert m/s to km/h?
Multiply by 3.6.
What is 10 m/s in km/h?
36 km/h.
What is 25 m/s in km/h?
90 km/h.
How many m/s is 1 km/h?
0.2778.
Does my number leave my device?
No, the calculation runs in your browser.
More pages and a wrap-up
For other speed conversions see Convert m/s to c, Convert m/s to mph, Convert mph to km/h, Convert knots to km/h, Convert km/h to knots, Convert km to mi, Convert mi to km, Convert °C to °F, Convert °F to °C. The reverse direction is Convert km/h to m/s.
In short, a “convert m/s to km/h” calculation means multiplying by 3.6 and writing the unit beside the answer. Your number is computed locally, with no account and no upload.