Speed limits, wind, boats, and treadmills may use km/h, mph, m/s, or knots. Convert definitions here for travel and sports reading.
km/h and mph
Swap road speeds without memorizing 1.609 factors.
Knots and m/s
Marine and weather knots vs SI m/s—handled on one page.
Pace vs speed units
For min/km from a race split, use the pace calculator.
Frequently asked questions
100 km/h in mph?
About 62.1 mph via exact factors—enter 100 km/h and convert to mph here.
What is a knot?
Knots are nautical miles per hour—common in aviation and marine speed. Convert knots with km/h or mph here.
Running pace vs km/h?
Min/km pace inverts to km/h (6 min/km ≈ 10 km/h). Convert km/h to mph here for US references.
When use m/s?
Physics and wind speed often use m/s. This page applies the 3.6 factor for you vs km/h.
Link to pace calculator?
This page converts speed units; for race pace from time and distance, try the pace calculator.
Can I save my inputs?
Yes. Copy link below the form keeps your current inputs so you can share the scenario or save it for later.