Convert a speed between road, wind and nautical units for travel and weather.
Try an example
Load a ready-made sample into this tool and run it. Every result you see is calculated live by the tool itself — nothing here is a pre-written answer.
Sample: value: 60; from: kmh; to: mph
How to Use
- Enter a speed value.
- Choose the current unit and the target unit.
- Read the converted speed.
What this speed converter does
This speed converter converts speeds between metres per second, kilometres per hour, miles per hour, and knots. Enter a value, choose its current unit and the one you need, and read the converted speed. It covers the units used on road signs, vehicle dashboards, weather reports, and boats, which differ by country and by whether the speed is measured on land, in the air, or at sea.
The relationships behind the conversion
One mile per hour is exactly 1.609344 kilometres per hour, and metres per second step to kilometres per hour by a factor of 3.6. A knot is one nautical mile per hour, the unit of maritime and aviation speed. These fixed relationships mean a speed limit, a wind report, and a boat's cruising speed can all be compared on one scale.
Good to know
Conversions use exact defined factors, including 1 mph equals 1.609344 km/h, and results are rounded to six decimal places. The converter changes the unit only; it does not calculate speed from a distance and time, so you need the speed itself as the starting value.
Frequently asked questions
How do I convert km/h to mph?
Enter the kilometres-per-hour value and convert to miles per hour. The tool divides by 1.609344, the exact defined relationship, so 100 km/h returns about 62.14 mph.
What is a knot in kilometres per hour?
A knot is one nautical mile per hour, equal to 1.852 kilometres per hour. Convert knots to kilometres per hour when a marine or aviation figure needs a land-based comparison.
Can this work out speed from distance and time?
No. This is a unit converter: it needs a speed as input and restates it in another unit. Divide distance by time first, then convert that speed here.
How to use Speed Converter
- Enter a speed value.
- Choose the current unit and the target unit.
- Read the converted speed.
Limitations
Conversions use exact defined factors (1 mph = 1.609344 km/h); results round to 6 decimal places.