FluffyBench

Speed Converter

Convert km/h, mph, meters per second and knots. 1 mph is exactly 1.609344 km/h, 1 knot is exactly 1.852 km/h, and 1 m/s is 3.6 km/h.

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From
To

Convert to

Units

Meters per secondm/sm/s
Kilometers per hourkm/hFrom
Miles per hourmphmph
Knotknkn

Other quantities have their own pages: Length, Mass, Temperature, Area, Volume, Pressure, Energy, Power and Data size.
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Need a speed in a different unit?

FluffyBench's Speed Converter switches a speed between km/h, mph, meters per second and knots as you type. The number changes, but the pace stays the same.

FluffyBench · 4 min read · Reviewed

Four speed units

Meters per second (m/s), Kilometers per hour (km/h), Miles per hour (mph), Knot (kn).

Every unit at once

Under the answer, FluffyBench lists your speed in the other units, each with its own Copy button.

Swap in one tap

The swap button between From and To reverses the direction and keeps your number.

Limits Input value takes a number; From and To set the units.

Why does a speed's number change with its unit?

Speed is distance covered in a stretch of time. Changing units is like describing the same journey with a different ruler and a different clock: the number changes, but the pace doesn't.

Here's how big one of each unit is, all measured in kilometers per hour. The longer the bar, the smaller the number that unit needs for the same speed.

1 m/s is exactly 3.6 km/h. 1 km/h is exactly 1 km/h. 1 mph is exactly 1.609344 km/h. 1 knot is exactly 1.852 km/h = 1,852 m/h because a nautical mile is exactly 1,852 meters.

Bars compare one of four speed units on a shared kilometer-per-hour scale

  1. Meters per second

    1 m/s is exactly 3.6 km/h.

  2. Kilometer per hour

    1 km/h is exactly 1 km/h.

  3. Mile per hour

    1 mph is exactly 1.609344 km/h.

  4. Knot

    1 knot is exactly 1.852 km/h = 1,852 m/h because a nautical mile is exactly 1,852 meters.

One of each unit, not four readings of one speed. How we measured

Converting a speed in FluffyBench's Speed Converter

Here's 1 knot converted to kilometers per hour, from choosing the units to copying the answer: 1 knot is exactly 1.852 km/h.

  1. FluffyBench's From and To unit buttons above the speed workspace.
    FluffyBench's From and To unit buttons above the speed workspace.
    Step 1. Start with the units: From is the unit your speed is in; To is the unit you want.
    1. Open From to pick your speed's unit.
    2. To picks the unit for the answer.
  2. The From picker lists meters per second, kilometers per hour, miles per hour and knot, each with its symbol.
    The From picker lists meters per second, kilometers per hour, miles per hour and knot, each with its symbol.
    Step 2. Choose Knot for a boat or flight speed. Picking a unit closes the list.
    1. Choose Knot (kn) as From.
  3. The To picker lists the speed units again; Knot is marked From.
    The To picker lists the speed units again; Knot is marked From.
    Step 3. Open To and choose Kilometers per hour.
    1. Choose Kilometers per hour (km/h) as To.
  4. Input value contains 1, with knots beside it.
    Input value contains 1, with knots beside it.
    Step 4. Type the number from your reading. The answer updates as you type; there's no Convert button. FluffyBench converts the number and doesn't check how the speed was measured.
    1. Type 1 in Input value.
    2. Check that the input says knots.
  5. The result reads 1.852 kilometers per hour, with Copy above it and the other speed units listed below.
    The result reads 1.852 kilometers per hour, with Copy above it and the other speed units listed below.
    Step 5. Read the answer in km/h. Copy takes the number only: 1.852, without km/h, and without the commas the page shows in big numbers.
    1. Read 1.852 kilometers per hour.
    2. Copy puts 1.852 on your clipboard.
    3. Each other unit has its own Copy button.

Check the speed before you use it

Copy gives you the number by itself. Before you paste, make sure the unit travels with it.

A real FluffyBench result shows 1.852 kilometers per hour. Copy puts 1.852 on the clipboard. An illustrated note reads Speed: 1.852 km/h, with km/h added by hand.
A field already labeled km/h needs only the number; a note or message needs the unit beside it.

Seeing a dash instead of an answer? Take any letters or unit symbols out of Input value: type 12.5, not 12.5 km/h. If your browser blocks the clipboard, FluffyBench says Copy was unavailable, and you can select the result and copy it yourself.

Need a distance instead of a speed?

Need a download speed in megabits or megabytes?

Why is 1 m/s equal to 3.6 km/h?

An hour has 3,600 seconds. Move 1 meter every second, and by the end of the hour you've gone 3,600 meters, which is 3.6 kilometers.

A row of 1-meter blocks, one for each second, adds up to 3,600 meters in 3,600 seconds: 3.6 kilometers in one hour, so 1 m/s equals 3.6 km/h.
Same pace, counted per second or per hour.

Why is a knot different from miles per hour?

A knot is one nautical mile per hour. A nautical mile is longer than the ordinary mile behind mph, so an hour at the same pace covers fewer of them, and the knot number comes out smaller: one knot is about 1.15 miles per hour.

Two bars on one meter scale: the statute mile behind mph ends at 1,609.344 meters, and the nautical mile behind knots ends at 1,852 meters. 1 knot is about 1.15 mph.
Both bars start at zero; the nautical mile is the longer one.
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