Speed Converter - km/h, mph, m/s, Knots, ft/s

Convert speeds between kilometers per hour, miles per hour, meters per second, knots, and feet per second, live as you type. Free, browser-based, with a reference table from walking pace to the speed of sound.

km/h

mph

m/s

knots

ft/s

100 km/h

= 100 km/h · 62.14 mph · 27.78 m/s · 54 knots · 91.13 ft/s

Reference	km/h	mph	m/s	knots
Casual walking	5	3.107	1.389	2.7
Jogging	10	6.214	2.778	5.4
Recreational cycling	20	12.43	5.556	10.8
City driving limit (much of Europe)	50	31.07	13.89	27
Usain Bolt's top sprint speed	44.7	27.78	12.42	24.14
Highway driving	120	74.56	33.33	64.79
High-speed train (ICE/TGV cruise)	300	186.41	83.33	161.99
Commercial jet cruise	900	559.23	250	485.96
Speed of sound at sea level (15 C)	1225	761.18	340.28	661.45

Speed Units and How They Relate

The five common speed units all describe distance per time, just with different base units. Kilometers per hour dominates road signs worldwide; miles per hour is used in the US and UK; meters per second is the SI unit used in physics and weather reports; knots (nautical miles per hour) rule aviation and shipping; and feet per second appears in ballistics and some engineering fields. The exact anchors: 1 mph = 1.609344 km/h, 1 knot = 1.852 km/h exactly, and 1 m/s = 3.6 km/h exactly.

Handy mental shortcuts: to go from km/h to m/s, divide by 3.6 (so a 100 km/h highway speed is about 27.8 m/s). To go from mph to km/h, multiply by 1.6 (60 mph is roughly 97 km/h). Knots sit between the two: 1 knot is about 1.15 mph. A ship doing 20 knots travels 37 km/h, and a jet cruising at 480 knots covers about 890 km/h. Wind speeds are a classic mix-up: Dutch and German forecasts often give wind in m/s or Beaufort, while aviation METARs use knots, so 10 m/s equals 36 km/h equals about 19 knots, a fresh breeze.

The nautical mile exists because it ties speed to geometry: one nautical mile (1852 m) is one minute of latitude, which makes chart navigation arithmetic clean. That is why both ships and aircraft kept knots even after metrication. The speed of sound, about 1225 km/h (Mach 1) at sea level and 15 C, drops with altitude and temperature, which is why airliners cruising at Mach 0.85 fly around 900 km/h rather than 1040.

Runners and cyclists usually think in pace (minutes per kilometer) rather than speed: 12 km/h equals a 5:00 min/km pace. The Running Pace Calculator on ToolForte converts between pace, time, and distance directly, and the general Unit Converter handles length, weight, and volume. All tools are free and run entirely in your browser.

How the Speed Converter Works

01Type a speed into any field: km/h, mph, m/s, knots, or ft/s.
02All other units convert instantly as you type.
03Read the combined result line for every unit at once.
04Use the reference table to place the speed between walking pace and the speed of sound.

Converting Between Speed Units

All five units express distance per time. The exact anchors: 1 m/s = 3.6 km/h, 1 mph = 1.609344 km/h, 1 knot = 1.852 km/h (one nautical mile per hour), and 1 ft/s = 0.3048 m/s. Kilometers per hour rules road signs in most of the world, mph covers the US and UK, m/s appears in physics and weather reports, knots dominate aviation and shipping, and ft/s shows up in engineering and ballistics. The converter normalizes everything through m/s for exact results.

When to Use This Tool

Use it to read US speed limits in km/h when driving abroad, interpret wind speeds given in m/s or knots, convert an aircraft's cruise speed from knots, translate treadmill km/h to mph, or check physics homework where everything must be in m/s. The reference table helps sanity-check results: if your conversion says a cyclist does 200 km/h, something went wrong.

Common Use Cases

Convert running speed to pace per kilometer for training → Running Pace Calculator
Read US road signs and car specs in familiar km/h
Convert aviation and sailing speeds from knots

Tips

km/h to m/s: divide by 3.6. mph to km/h: multiply by about 1.6.
Knots sit between the big two: 1 knot is 1.85 km/h or 1.15 mph.
Sanity-check with the reference table; everyday speeds have familiar anchors.

Frequently Asked Questions

How do I convert km/h to m/s?→

Divide by 3.6. A car doing 90 km/h moves at 25 m/s. Going the other way, multiply by 3.6: a sprinter at 10 m/s is running 36 km/h. The factor is exact because one hour is 3600 seconds and one kilometer is 1000 meters.

What exactly is a knot?→

One nautical mile per hour, where a nautical mile is exactly 1852 meters, about one minute of latitude. So 1 knot = 1.852 km/h = 1.15 mph. Ships and aircraft use knots because nautical miles fit chart-based navigation neatly.

How fast is 60 mph in km/h?→

60 mph is 96.6 km/h, using the exact factor 1 mile = 1.609344 km. Common US limits: 55 mph is about 88 km/h, 65 mph about 105 km/h, and 70 mph about 113 km/h.

How fast is the speed of sound?→

About 1225 km/h (761 mph, 340 m/s) at sea level and 15 C. It drops with temperature, so at typical cruise altitude it is closer to 1060 km/h. That is why an airliner at Mach 0.85 flies about 900 km/h.

Are wind speeds given in m/s, km/h, or knots?→

It depends on the country and context. Dutch and Nordic forecasts often use m/s, most public forecasts elsewhere use km/h or mph, and aviation weather (METAR) uses knots. As anchors: 10 m/s = 36 km/h = 19.4 knots, a fresh breeze at Beaufort 5.

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