What is a Mile per Hour?

Miles per hour is the road-speed standard in the United States, the United Kingdom, and several Caribbean countries.

Overview

Miles per hour is the road-speed standard in the United States, the United Kingdom, and several Caribbean countries. American and British road signs, car speedometers, and weather reports use mph. Typical US speed limits are 25 mph (residential), 35–45 mph (urban arterials), 55–65 mph (rural highways), and 65–80 mph (interstates). The UK uses mph despite metric measurement elsewhere — a result of incomplete metrication. Mph derives from the mile (distance) and hour (time): 1 mph ≈ 1.609 km/h ≈ 0.447 m/s. World-class sprinters reach about 27 mph, professional baseball pitchers throw at 90–105 mph, and commercial airliners cruise at 550–600 mph. The unit relates to km/h (1 mph ≈ 1.609 km/h), m/s (1 mph ≈ 0.447 m/s), the knot (1 mph ≈ 0.869 kn), and ft/s (1 mph ≈ 1.467 fps).

Symbol

mph

Convert Mile per Hour to all units

Live result

mph

Kilometer per Hour1.609344 km/h Meter per Second0.44704 m/s Knot0.868976 kn Mach0.001314 Ma Foot per Second1.466667 ft/s Centimeter per Second44.704 cm/s Yard per Minute29.333333 yd/min Inch per Minute1,056.8322 in/min Beaufort Scale0.44704 Bft

Relationship to Other Speed Units

1 mph equals

Visual reference for how the mile per hour relates to other speed units. Each row links to the full converter for that pair.

1 mph=1.609344 km/h 1 mph=0.44704 m/s 1 mph=0.868976 kn 1 mph=0.001314 Ma 1 mph=1.466667 ft/s 1 mph=44.704 cm/s 1 mph=29.333333 yd/min 1 mph=1,056.8322 in/min 1 mph=0.44704 Bft

When Is the Mile per Hour Used?

US and UK road speed limits
US car speedometers
US baseball pitch speeds

Real-world examples

US interstate: 70 mph typical. UK motorway: 70 mph limit. Cycling pro speed: 25 mph. Tornado winds: 110+ mph.

Tips for Using the Mile per Hour

1 mph = 1.609 km/h = 0.447 m/s.
Quick convert: mph × 1.6 = km/h.
UK speeds posted in mph on road signs despite general metrication.

Common Mistakes

Reading a UK road sign "50" as km/h — it's mph (= 80 km/h).
Converting mph to km/h by multiplying by 1.5 instead of 1.609 — 7% error.
Assuming "mph" and "MPH" differ — capitalisation does not matter.

Convert Mile per Hour to Other Speed Units

Mile per Hour to Kilometer per Hour

1 mph = 1.609344 km/h

Mile per Hour to Meter per Second

1 mph = 0.44704 m/s

Mile per Hour to Knot

1 mph = 0.868976 kn

Mile per Hour to Mach

1 mph = 0.001314 Ma

Mile per Hour to Foot per Second

1 mph = 1.466667 ft/s

Mile per Hour to Centimeter per Second

1 mph = 44.704 cm/s

Mile per Hour to Yard per Minute

1 mph = 29.333333 yd/min

Mile per Hour to Inch per Minute

1 mph = 1,056.8322 in/min

Mile per Hour to Beaufort Scale

1 mph = 0.44704 Bft

Convert Other Units to Mile per Hour

Kilometer per Hour to Mile per Hour

1 km/h = 0.621371 mph

Meter per Second to Mile per Hour

1 m/s = 2.236936 mph

Knot to Mile per Hour

1 kn = 1.150779 mph

Mach to Mile per Hour

1 Ma = 761.20705 mph

Foot per Second to Mile per Hour

1 ft/s = 0.681818 mph

Centimeter per Second to Mile per Hour

1 cm/s = 0.022369 mph

Yard per Minute to Mile per Hour

1 yd/min = 0.034091 mph

Inch per Minute to Mile per Hour

1 in/min = 0.000946 mph

Beaufort Scale to Mile per Hour

1 Bft = 2.236936 mph

FAQ About the Mile per Hour

3 questions

What does the Mile per Hour (mph) measure?

The mile per hour measures speed. Miles per hour is the road-speed standard in the United States, the United Kingdom, and several Caribbean countries.

When is the Mile per Hour used?

The mile per hour is used in: US and UK road speed limits; US car speedometers; US baseball pitch speeds. US interstate: 70 mph typical. UK motorway: 70 mph limit. Cycling pro speed: 25 mph. Tornado winds: 110+ mph.

How accurate are conversions involving the Mile per Hour?

All conversions on Units Converter use NIST SP 811 and BIPM reference values, accurate to 8 significant figures.