Closing summary
The Speed Converter converts speed units for road travel, aviation, and science. Miles per hour, kilometres per hour, knots, feet per second, and metres per second share one factor table with steps shown on every result.
Physics velocity solvers compute speed from distance and time. This page only re-labels a speed value already known in another unit.
Convert between units of speed
Enter a numeric speed and pick source and target units. The Speed Converter multiplies by the ratio from the audited table, for example converting 60 mph to km/h uses 60 × 1.609344 = 96.56064 km/h. Results recalculate live when either field changes.
Feet per second and metres per second appear for engineering and sport timing. Knots appear for marine and air speed references tied to nautical miles per hour.
Convert mph to km/h
One mile per hour equals exactly 1.609344 kilometres per hour under the international mile definition. Fifty-five mph converts as 55 × 1.609344 = 88.51392 km/h, the figure often printed on US vehicle dashboards beside the mph scale. Reverse conversion divides by 1.609344.
One hundred km/h equals 100 ÷ 1.609344 ≈ 62.137 mph. The Speed Converter shows both directions with the same factor line.
Convert knots to mph
One knot is one nautical mile per hour, defined as 1852 metres per hour. That equals 1.150779448 mph and 1.852 km/h exactly. Thirty knots convert to 30 × 1.150779 ≈ 34.523 mph for a quick wind or boat speed comparison to road units.
Aviation charts often list knots; drivers think in mph or km/h. The converter bridges those labels without re-deriving the nautical mile length.
See a speed in every unit
Cascade view lists mph, km/h, knots, m/s, and ft/s for one entry. Eighty-eight km/h appears as 54.68 mph, 47.51 knots, 24.44 m/s, and 80.21 ft/s in the same panel. Each column uses the same underlying SI speed in metres per second, then formats outward.
Changing the input unit updates every column simultaneously so mismatched labels are easy to spot.
Convert metres per second and feet per second
Sprinters and wind tunnel reports often cite m/s while US weather bulletins still mix mph. One m/s equals 3.280839895 ft/s and 2.236936292 mph exactly from length definitions. The Speed Converter routes through SI speed internally so m/s and ft/s stay consistent with mph and km/h on the cascade panel.
A track segment at 10 m/s is 36 km/h or 22.37 mph, useful when comparing lab data to road speed limits without re-entering the value in each unit separately.
Read common speed conversions
| Input | mph | km/h | knots |
|---|---|---|---|
| 1 mph | 1 | 1.609 | 0.869 |
| 60 mph | 60 | 96.56 | 52.14 |
| 100 km/h | 62.14 | 100 | 54.00 |
| 30 knots | 34.52 | 55.56 | 30 |
Rows round for display; the calculator uses full precision from the audited table. Click a row when the product supports loading preset values.
Relate speed limits across regions
A 50 km/h urban limit equals about 31.07 mph. A 70 mph rural limit equals about 112.65 km/h. The Speed Converter lets policy comparisons use exact factors instead of memorized approximations that drift between countries.
FAQ
How do I convert mph to km/h?
Multiply miles per hour by 1.609344 to get kilometres per hour. Sixty mph becomes 96.56064 km/h. The Speed Converter performs the multiply and shows the working line.
How many km/h is 1 mph?
One mph equals 1.609344 km/h exactly. Dividing km/h by the same factor returns mph.
What is a knot in mph?
One knot equals 1.150779448 mph, because one nautical mile is 1852 metres and one international mile is 1609.344 metres. The Speed Converter uses the exact nautical definition.
How do I convert m/s to mph?
Multiply metres per second by 2.2369362920544 to get mph, or use the unit picker. Ten m/s is about 22.37 mph, a common sprint reference.
Is this the same as the physics velocity calculator?
No. The physics Velocity Calculator solves for speed from distance and time or related kinematics inputs. The Speed Converter only converts a speed already expressed in one unit into another.
Which factor does the Speed Converter use for miles?
The international mile of 1609.344 metres, matching US and UK road sign conversions to km/h on modern vehicles.
How fast is 100 km/h in mph?
One hundred km/h equals 100 divided by 1.609344, about 62.137 mph. The Speed Converter shows the division step on the result panel.
Can I convert km/h to knots?
Divide km/h by 1.852 to get knots. One hundred km/h is about 54 knots. The unit picker performs the same ratio without manual setup.
What is 25 mph in m/s?
Twenty-five mph divided by 2.2369362920544 equals about 11.18 m/s. The Speed Converter shows mph to m/s through the shared factor table.
The Speed Converter returns the converted value with the factor and working shown, so every result can be checked by hand against the audited conversion table.