CONVERTERS / SPEED & MOTION
Speed Converter for km/h, mph and More
Switch effortlessly between kilometers per hour, miles per hour, meters per second, feet per second, and knots. Compare equivalent speeds, understand the formulas, and explore practical reference values in one place.
Convert between speed units
Convert road, running, aviation, and engineering speeds.
Enter a speed
Results update when you click Convert speed.
Try a common example
Converted speed
60 mph
Equivalent speeds in all supported unitsEquivalent values
Hover or focus a card to highlight the corresponding speed unit. Select a card to convert from that unit.
Speed in context
Illustrations connect the converted number with familiar motion concepts.
Speed reference table
Common reference speeds converted into every supported unit.
| Reference | km/h | mph | m/s | ft/s | kn |
|---|---|---|---|---|---|
| Walking | 5 | 3.11 | 1.39 | 4.56 | 2.7 |
| Urban cycling | 15 | 9.32 | 4.17 | 13.67 | 8.1 |
| City traffic | 50 | 31.07 | 13.89 | 45.57 | 27 |
| Highway | 104.61 | 65 | 29.06 | 95.33 | 56.48 |
| Aircraft | 833.4 | 517.85 | 231.5 | 759.51 | 450 |
Rounding note: calculations use the underlying conversion factors. Displayed values are rounded to four decimal places for readability.
01 / THE BASICS
Understand speed before converting it
Speed tells you how much distance an object travels over a period of time. The same physical motion can be described using different units, which is why converting between km/h, mph, m/s, ft/s and knots is useful.
For example, a car traveling at 100 km/h is moving at approximately 62.14 mph or 27.78 m/s. The numbers differ because the units differ; the underlying speed remains the same.
One speed, different expressions
Converting units changes the numerical representation of a measurement, not the actual motion being described.
02 / KNOW YOUR UNITS
The five speed units explained
Each unit is useful in a different context. Explore the cards to compare their conversion factors and common applications.
01 / UNIT
km/h
Kilometers per hour
1 km/h = 0.277778 m/s
Road signs and vehicle speedometers in many countries.
02 / UNIT
mph
Miles per hour
1 mph = 0.44704 m/s
Road speeds in the United States and some other regions.
03 / UNIT
m/s
Meters per second
1 m/s = 1 m/s
Physics, engineering, sports science and SI calculations.
04 / UNIT
ft/s
Feet per second
1 ft/s = 0.3048 m/s
Technical measurements that use feet as the distance unit.
05 / UNIT
kn
Knots
1 kn = 0.514444… m/s
Aircraft, ships and marine navigation.
For a broader understanding of measurement systems, explore the length conversion tool and other conversion tools.
03 / HOW IT WORKS
How the speed conversion formula works
The converter uses meters per second as a common reference unit. First, the original value is converted to m/s. The intermediate value is then converted into the selected target unit.
STARTOriginal speedEnter a value and unit
COMMON BASEMeters per secondConvert using the exact unit factor
FINISHTarget speedExpress the same speed in another unit
FORMULA A
km/h to m/s
km/h ÷ 3.6
Divide kilometers per hour by 3.6.
72 km/h = 20 m/s
FORMULA B
m/s to km/h
m/s × 3.6
Multiply meters per second by 3.6.
20 m/s = 72 km/h
FORMULA C
mph to km/h
mph × 1.609344
Multiply miles per hour by the exact factor.
60 mph = 96.5616 km/h
General formula
Target value = original value × (source unit in m/s ÷ target unit in m/s).
The calculator applies the conversion factors before rounding the displayed result.
04 / SPEED IN REAL LIFE
Compare familiar speeds visually
The examples below help put common speed values into perspective. Longer bars represent larger values in km/h, making it easier to compare the reference speeds at a glance.
01
Slow walkingGentle walking pace
3 km/h1.9 mph0.83 m/s
02
Brisk walkingPurposeful walking
5 km/h3.1 mph1.39 m/s
03
Easy runningIllustrative running pace
10 km/h6.2 mph2.78 m/s
04
City cyclingTypical example, varies widely
20 km/h12.4 mph5.56 m/s
05
Urban trafficIllustrative road speed
50 km/h31.1 mph13.89 m/s
06
Highway drivingIllustrative road speed
100 km/h62.1 mph27.78 m/s
These are illustrative reference speeds, not universal averages or recommended travel speeds. The scale is normalized to 100 km/h.
05 / REFERENCE DATA
Speed conversion table
Use this table to look up frequently used speeds without entering each value separately. Values are rounded to two decimal places for readability.
QUICK REFERENCEAll values describe the same speed across units
| km/h | mph | m/s | ft/s | Knots |
|---|---|---|---|---|
| 5 | 3.11 | 1.39 | 4.56 | 2.7 |
| 10 | 6.21 | 2.78 | 9.11 | 5.4 |
| 20 | 12.43 | 5.56 | 18.23 | 10.8 |
| 30 | 18.64 | 8.33 | 27.34 | 16.2 |
| 50 | 31.07 | 13.89 | 45.57 | 27 |
| 60 | 37.28 | 16.67 | 54.68 | 32.4 |
| 80 | 49.71 | 22.22 | 72.91 | 43.2 |
| 100 | 62.14 | 27.78 | 91.13 | 54 |
| 120 | 74.56 | 33.33 | 109.36 | 64.79 |
Conversion values are calculated from standard unit relationships. Small differences in the final displayed digits can occur because the table rounds values.
06 / WORKED EXAMPLES
Step-by-step speed conversions
Follow these examples to see how the conversion factors work. You can then enter your own value in the calculator above.
Convert 100 km/h to mph
1
Start with 100 km/h.
2
Divide by 1.609344.
3
100 ÷ 1.609344 ≈ 62.1371.
ANSWER62.14 mph
Convert 15 m/s to km/h
1
Start with 15 m/s.
2
Multiply by 3.6.
3
15 × 3.6 = 54.
ANSWER54 km/h
Convert 20 knots to km/h
1
Start with 20 knots.
2
Multiply by 1.852.
3
20 × 1.852 = 37.04.
ANSWER37.04 km/h
07 / UNDERSTANDING MOTION
Speed, distance, and time explained
Speed connects the distance traveled with the time taken. If an object moves at a constant speed, the relationship can be rearranged to calculate any one of these three quantities when the other two are known. For a reference on standard measurement units, consult the National Institute of Standards and Technology’s SI units guide.
THE BASIC RELATIONSHIPDistance = Speed × Time
Find speedDistance ÷ Time
Find timeDistance ÷ Speed
For example, traveling 120 kilometers at a constant 60 km/h takes 2 hours: 120 ÷ 60 = 2. Make sure the units match—kilometers with kilometers per hour, for instance.
You can also use the elapsed-time calculator to work with elapsed time, or the length converter when your distance is in another unit.
08 / AVOID COMMON MISTAKES
What to know before converting speed
Multiplying when you should divide
Converting km/h to m/s requires division by 3.6. Converting m/s to km/h requires multiplication by 3.6.
Mixing units in distance-time calculations
A distance in miles should be paired with speed in miles per hour if you want the time in hours.
Confusing speed with velocity
Speed describes how fast something moves. Velocity also includes the direction of motion.
Rounding too early
Use the full conversion factor during the calculation and round only the final displayed value.
09 / FREQUENTLY ASKED QUESTIONS
Speed converter FAQs
How do I convert km/h to mph?
Divide kilometers per hour by 1.609344, or multiply by approximately 0.621371. For example, 100 km/h is approximately 62.14 mph.
How do I convert mph to km/h?
Multiply miles per hour by 1.609344. For example, 60 mph equals 96.5616 km/h.
How many km/h are in one knot?
One knot equals exactly 1.852 km/h. A knot represents one nautical mile per hour and is commonly used in aviation and maritime navigation.
Why is m/s used as the conversion base?
Meters per second is the SI unit for speed. Using a consistent base unit makes it straightforward to convert between different measurement systems.
Can I convert zero or decimal values?
Yes. Zero and non-negative decimal values are valid. Negative speeds are not accepted by this calculator.
Are the displayed conversion results exact?
The conversion factors are used before the results are formatted. Displayed values are rounded for readability, so additional decimal places may exist beyond those shown.
Reference speeds are illustrative, and conversions are based on standard unit relationships. Real-world speeds vary by conditions and context. Displayed values may be rounded.