Speed converter
Convert between kilometers per hour, miles per hour, meters per second, knots, and other speed units. Interpret speed limits abroad, compare athlete splits, or translate wind speeds in weather reports. 100 km/h ≈ 62.14 mph — a common highway reference.
Value
From
km/h
m/s
mph
knot
To
km/h
m/s
mph
knot
Result
0.62 mph
How to convert speed units
1. Enter speed in the source unit (e.g. km/h).
2. Select the target unit (e.g. mph).
3. Use m/s for physics problems and mph or km/h for road travel.
4. For running pace, convert to min/km or min/mile separately if needed.
Speed conversion examples
Highway limit
130 km/h (common EU limit) = 80.78 mph. US interstate 65 mph = 104.6 km/h.
Marathon pace
12 km/h = 7.46 mph — roughly 5:00 min/km pace.
Knots (aviation/marine)
450 knots = 833.4 km/h ≈ 517.8 mph. 1 knot = 1 nautical mile per hour.
When to use the speed converter
• When you drive or cycle in a country using unfamiliar speed units.
• When you compare vehicle specs or wind gusts across unit systems.
• When you convert m/s from physics homework to km/h for intuition.
When to choose something else
• When you need pace as time per distance — invert speed or use a pace calculator.
• When you need angular velocity (rad/s) — different dimension.
• When you calculate stopping distance — needs reaction time and deceleration.
Nautical miles vs statute miles
Knots tie to nautical miles (1852 m), slightly longer than statute miles (1609 m). That is why 100 knots exceeds 100 mph. Marine charts and aviation flight plans use knots for consistency with nautical distance.
From speed to travel time
Time = distance ÷ speed. At steady 90 km/h, 450 km takes 5 hours. Convert units before dividing — do not mix km with mph in one formula without converting first.
Frequently asked questions
How do I convert km/h to mph?
Multiply km/h by 0.621371192 (or divide mph by the same to get km/h).
What is a knot?
One nautical mile per hour ≈ 1.852 km/h. Used in aviation and shipping.
How does m/s relate to km/h?
Multiply m/s by 3.6 to get km/h. Example: 10 m/s = 36 km/h.
Is speed the same as velocity?
Speed is magnitude only; velocity includes direction. This converter handles scalar speed.
Mach number?
Mach depends on air temperature and speed of sound — not a fixed ratio to mph.
Is data uploaded?
No. Conversions run locally.