What is 100 km/h in m/s?

27.7777777778 m/s: a car at 100 km/h covers a little under 28 metres in every second. The speeds either side of it come out as 90 km/h is 25 m/s exactly, 110 km/h is 30.5555555556, 120 km/h is 33.3333333333 and 130 km/h is 36.1111111111. Going back, 30 m/s is 108 km/h.

What is the formula for km/h to m/s?

m/s = km/h x 1000 / 3600, which reduces to km/h / 3.6, or the exact fraction km/h x 5 / 18. The converter stores a kilometre per hour as 1/3.6 metres per second and works from there, so both directions use the same number: km/h = m/s x 3.6. Press swap and 1 m/s gives 3.6 km/h, 10 m/s gives 36 and 25 m/s gives 90.

How do I convert km/h to m/s in my head?

Multiply by 5 and divide by 18, since 5/18 is exactly 1/3.6. For 90 km/h that is 450 / 18 = 25 m/s, and for 72 km/h it is 360 / 18 = 20 m/s. A rougher route is to divide by 4 and add a bit back: 100 / 4 is 25, and the true answer is 27.7777777778, about 11 percent higher, so the quarter rule undershoots by a tenth every time.

Which speeds convert to a whole number of m/s?

The multiples of 3.6 km/h: 3.6 km/h gives 1 m/s, 18 gives 5, 36 gives 10, 72 gives 20, 90 gives 25 and 108 gives 30. Other inputs can have either short or repeating decimals: 1.8 km/h is exactly 0.5 m/s and 2.52 km/h exactly 0.7 m/s, while 5 km/h displays as 1.38888888889 m/s, 20 km/h as 5.55555555556 m/s and 50 km/h as 13.8888888889 m/s. The display rounds beyond twelve significant digits.

Why do physics problems want m/s rather than km/h?

Because the metre and the second are the SI base units, so a speed in m/s drops straight into v = d / t, into an acceleration in m/s squared and into a kinetic energy in joules without a second conversion. That is the whole job of this page: read the speed off a sign or a dashboard in km/h, convert once, and keep working in metres and seconds.

Is the conversion exact, or is it rounded?

The size ratio is exactly 5/18 m/s per km/h, using exactly 1,000 m per km and 3,600 s per hour. Decimal-rational arithmetic preserves the written input. One km/h has a repeating output displayed as 0.277777777778 m/s; outputs beyond twelve significant digits round even if the decimal terminates. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units.

How do I get mph, knots or ft/s at the same time?

They are already there. Under the headline the page lists the same speed in every other unit it holds for speed, each with its own Copy button, so 100 km/h reads 62.1371192237 mph, 53.9956803456 knots and 91.1344415281 feet per second alongside its 27.7777777778 m/s. Pick any of them in the To menu to promote it to the headline instead.

Can I convert m/s back to km/h here?

Yes, in one press. The swap button between the two boxes reverses the pair and the page becomes an m/s to km/h converter: 1 m/s is 3.6 km/h, 5 m/s is 18, 25 m/s is 90 and a supplied 343 m/s is 1,234.8 km/h. Both unit menus stay open throughout, so you can send the same figure to knots or feet per second without leaving. Unit conversion does not establish an actual sound speed, medium or measurement condition.

Why does the page open on km/h and m/s when I last converted something else?

This focused page opens on Kilometer per hour and Meter per second, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen.

Does anything I type leave the browser?

Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account.

KPH to m/s Converter

A kilometre per hour is 1,000 metres spread over 3,600 seconds, so kph to m/s is one division: m/s = km/h / 3.6. The factor comes out of those definitions rather than a measurement, so the factor is exact and outputs round when needed, but one divided by 3.6 never terminates: 1 km/h prints as 0.277777777778 m/s at the twelve significant digits the converter shows, and 100 km/h as 27.7777777778 m/s. Multiples of 3.6 land clean, which is the quickest sanity check on any answer: 3.6 km/h is 1 m/s, 18 km/h is 5, 36 km/h is 10, 72 km/h is 20 and 108 km/h is 30. This page opens the converter with Kilometer per hour in the From box and Meter per second in the To box, ahead of whatever pair you last used, and the same speed appears under the answer in miles per hour, feet per second and knots, so 100 km/h reads 27.7777777778 m/s, 62.1371192237 mph, 91.1344415281 ft/s and 53.9956803456 kn on one screen. The swap button between the boxes turns the page into an m/s to km/h converter, where 1 m/s is 3.6 km/h and 25 m/s is 90.

From

To0.277777777778

Category: Speed

Base unit: meter per second

A knot is one international nautical mile (1,852 meters) per hour. These are speed units, not pace in minutes per distance.

Results round to 12 significant digits using the listed unit definitions. Input must have a finite numeric magnitude and at most 512 significant digits. Type a single decimal or scientific number; a matching From unit suffix is accepted. Commas and grouped spaces separate thousands; decimal commas, fractions and compound measurements are refused.

1 km/h in every speed unit

Meter per secondm/s
0.277777777778
Mile per hourmph
0.621371192237
Foot per secondft/s
0.911344415281
Knotkn
0.539956803456

Selectable complete conversion

Unit Converter — Speed
Input: 1 (Kilometer per hour, km/h)
Result: 0.277777777778 m/s (Meter per second)
Displayed values round to 12 significant digits.
A knot is one international nautical mile (1,852 meters) per hour. These are speed units, not pace in minutes per distance.
All other units:
Meter per second (m/s): 0.277777777778
Mile per hour (mph): 0.621371192237
Foot per second (ft/s): 0.911344415281
Knot (kn): 0.539956803456

Common questions

What is 100 km/h in m/s?: 27.7777777778 m/s: a car at 100 km/h covers a little under 28 metres in every second. The speeds either side of it come out as 90 km/h is 25 m/s exactly, 110 km/h is 30.5555555556, 120 km/h is 33.3333333333 and 130 km/h is 36.1111111111. Going back, 30 m/s is 108 km/h.
What is the formula for km/h to m/s?: m/s = km/h x 1000 / 3600, which reduces to km/h / 3.6, or the exact fraction km/h x 5 / 18. The converter stores a kilometre per hour as 1/3.6 metres per second and works from there, so both directions use the same number: km/h = m/s x 3.6. Press swap and 1 m/s gives 3.6 km/h, 10 m/s gives 36 and 25 m/s gives 90.
How do I convert km/h to m/s in my head?: Multiply by 5 and divide by 18, since 5/18 is exactly 1/3.6. For 90 km/h that is 450 / 18 = 25 m/s, and for 72 km/h it is 360 / 18 = 20 m/s. A rougher route is to divide by 4 and add a bit back: 100 / 4 is 25, and the true answer is 27.7777777778, about 11 percent higher, so the quarter rule undershoots by a tenth every time.
Which speeds convert to a whole number of m/s?: The multiples of 3.6 km/h: 3.6 km/h gives 1 m/s, 18 gives 5, 36 gives 10, 72 gives 20, 90 gives 25 and 108 gives 30. Other inputs can have either short or repeating decimals: 1.8 km/h is exactly 0.5 m/s and 2.52 km/h exactly 0.7 m/s, while 5 km/h displays as 1.38888888889 m/s, 20 km/h as 5.55555555556 m/s and 50 km/h as 13.8888888889 m/s. The display rounds beyond twelve significant digits.
Why do physics problems want m/s rather than km/h?: Because the metre and the second are the SI base units, so a speed in m/s drops straight into v = d / t, into an acceleration in m/s squared and into a kinetic energy in joules without a second conversion. That is the whole job of this page: read the speed off a sign or a dashboard in km/h, convert once, and keep working in metres and seconds.
Is the conversion exact, or is it rounded?: The size ratio is exactly 5/18 m/s per km/h, using exactly 1,000 m per km and 3,600 s per hour. Decimal-rational arithmetic preserves the written input. One km/h has a repeating output displayed as 0.277777777778 m/s; outputs beyond twelve significant digits round even if the decimal terminates. Copy result copies the displayed headline without digit-grouping commas; each visible conversion row has its own Copy button. Displayed and copied values round to twelve significant digits. If native copying fails, a complete selectable summary identifies the input, selected pair and conventions and includes every unit in the category, including uncommon units.
How do I get mph, knots or ft/s at the same time?: They are already there. Under the headline the page lists the same speed in every other unit it holds for speed, each with its own Copy button, so 100 km/h reads 62.1371192237 mph, 53.9956803456 knots and 91.1344415281 feet per second alongside its 27.7777777778 m/s. Pick any of them in the To menu to promote it to the headline instead.
Can I convert m/s back to km/h here?: Yes, in one press. The swap button between the two boxes reverses the pair and the page becomes an m/s to km/h converter: 1 m/s is 3.6 km/h, 5 m/s is 18, 25 m/s is 90 and a supplied 343 m/s is 1,234.8 km/h. Both unit menus stay open throughout, so you can send the same figure to knots or feet per second without leaving. Unit conversion does not establish an actual sound speed, medium or measurement condition.
Why does the page open on km/h and m/s when I last converted something else?: This focused page opens on Kilometer per hour and Meter per second, while preserving the main converter’s saved unit pair. When storage is usable, a saved value and uncommon-unit preference can travel between pages. Its suffix must still match From. Valid deliberate scalar edits can save those fields after a short delay; invalid or incomplete drafts preserve the saved record. Unusable or conflicting records remain until you use Forget saved settings, which keeps the current conversion on screen.
Does anything I type leave the browser?: Your input and converted values are calculated in the browser and are not uploaded by the converter. The definitions arrive with the page, so conversion needs no external data lookup and keeps working offline after the page has loaded. The core conversion needs no account.

Results round to 12 significant digits using the listed unit conventions. Many factors are exact definitions; psi and parsec use rounded coefficients. Temperature includes scale offsets. Days and weeks are fixed-duration units, and unit conversion does not determine calendar dates, ambient pressure or a software label’s convention.