Speed Converter - MPH, KPH, Knots & Mach Calculator
🚗 Transport & Science

Speed Converter & Velocity Tool

The ultimate velocity calculator. Convert accurately between MPH, KM/H, Knots, and Mach numbers. Perfect for physics calculations, driving abroad, or aviation planning.

Velocity Engine

Enter speed to convert instantly.

🏎️ Speed Value
🎯 Decimal Precision
CONVERTED SPEED
96.56
km/h
Conversion Formula:
1 mph ≈ 1.6093 km/h
Meters/Sec 26.82 m/s
⚓
Knots 52.14 kn
✈️
Mach 0.08 M

Common Speed Limits & Standards

Knowing how speed units compare is vital for travel and safety. 100 km/h is significantly slower than 100 mph.

🛣️
Highway (Metric)

100 km/h is approx 62 mph. (Standard in Canada, Australia, Europe).

🇺🇸
Highway (US/UK)

60 mph is approx 97 km/h. 70 mph is 113 km/h.

🏙️
City Limits

30 mph ≈ 50 km/h. This is the standard urban limit worldwide.

Speed Conversion Formulas

Conversion Multiplier Reverse
MPH to KM/H × 1.60934 ÷ 1.60934
MPH to Knots ÷ 1.15078 × 1.15078
KM/H to M/S ÷ 3.6 × 3.6
Knots to KM/H × 1.852 ÷ 1.852

Special Units: Knots & Mach

⚓

The Knot (kn)

Used in aviation and maritime. 1 Knot = 1 Nautical Mile per hour. It is based on the curvature of the Earth (1 minute of latitude).

🚀

Mach Number

Mach 1 is the speed of sound (approx 343 m/s or 767 mph at sea level). It varies with temperature and altitude.

🏃

Usain Bolt

The fastest human footspeed is approx 44.72 km/h (27.8 mph), achieved during a 100m sprint.

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Frequently Asked Questions

What is 100 kmh in mph?
100 km/h is equal to 62.14 mph. This is a very common conversion for drivers crossing between Canada/Europe and the US/UK.
Why do planes use Knots?
Knots are based on Nautical Miles, which map directly to degrees of latitude on the Earth. This makes navigation and map reading much easier for pilots and sailors.
How fast is Mach 1?
At standard sea level conditions (15°C), Mach 1 is approximately 340.3 meters per second, or 1225 km/h (761 mph).
How do I convert m/s to km/h?
Multiply by 3.6. For example, 10 m/s × 3.6 = 36 km/h. To go the other way, divide km/h by 3.6.
Is a Nautical Mile longer than a regular Mile?
Yes. 1 Nautical Mile is 1.852 km (approx 1.15 regular miles). Therefore, 1 Knot (1.852 km/h) is faster than 1 MPH (1.609 km/h).
What is the speed of light?
The speed of light in a vacuum is exactly 299,792,458 m/s. This is approximately 670 million mph or Mach 874,030.
What is 55 mph in km?
55 mph is 88.5 km/h. This was the National Maximum Speed Limit in the US between 1974 and 1995.
How fast is a brisk walk?
A typical brisk walking speed is about 5 km/h or 3.1 mph.
Do any countries use MPH besides the US?
Yes. The United Kingdom also uses MPH for speed limits on road signs, despite being officially metric in many other areas.
How accurate is this converter?
This tool uses precise conversion factors (e.g., 1 inch = 2.54 cm exactly) to calculate speeds up to 9 decimal places of accuracy.