# Miles per hour

Miles per hour
Automobile speedometer, indicating speed in miles per hour
Unit information
Unit system Imperial, United States customary units
Unit of speed
Symbol mph
Unit conversions
1 mph in ... ... is equal to ...
km/h    1.609344
m/s    0.44704
knot    0.868976
ft/s    1.467

Miles per hour (abbreviated mph, MPH or mi/h) is an imperial and United States customary unit of speed expressing the number of statute miles covered in one hour. It is used in the United States, United Kingdom and many Commonwealth nations, particularly in the Caribbean region.

## Usage

United States road sign with maximum speed noted in standard mph
United Kingdom road sign with maximum speed shown in mph

Speed limits and road traffic speeds in some countries and territories are indicated in miles per hour, as follows (all other countries use kilometers per hour):

Road traffic speeds in other countries are indicated in kilometres per hour, while occasionally both systems are used. For example, in Ireland, a judge considered a speeding case by examining speeds in both kilometres per hour and miles per hour. The judge was quoted as saying the speed seemed "very excessive" at 180 km/h but did not look "as bad" at 112 mph; a reduced fine was still imposed on the speeding driver.[19]

### Rail networks

Miles per hour is the unit also used in the Canadian rail system,[20] which uses km/h on roads.

### Nautical and aeronautical usage

Nautical and aeronautical applications favour the knot as a common unit of speed. (One knot is one nautical mile per hour, with a nautical mile being exactly 1,852 meters or about 6,076 feet.)

### Other usage

In some countries mph may be used to express the speed of delivery of a ball in sporting events such as cricket, tennis and baseball.

## Conversions

 1 mph = 0.44704 m/s (exactly) = 1.609344 km/h (exactly) ≈ 1.467 ft/s (approximately) ≈ 0.868976 kn
Conversions between common units of speed
m/s km/h mph knot ft/s
1 m/s = 1 3.6 2.236936 1.943844 3.280840
1 km/h = 0.277778 1 0.621371 0.539957 0.911344
1 mph = 0.44704 1.609344 1 0.868976 1.466667
1 knot = 0.514444 1.852 1.150779 1 1.687810
1 ft/s = 0.3048 1.09728 0.681818 0.592484 1

(Values in bold face are exact.)

## References

1. ^ Speed limits Archived 2015-03-22 at the Wayback Machine. (UK) Department for Transport. Retrieved 4 August 2015
2. ^ "Welcome to The BVI Beacon Online". Bvibeacon.com. 2005-12-01. Archived from the original on 2015-04-02. Retrieved 2014-08-21.
3. ^ "Speed limit changes start Monday | Cayman Compass". www.caymancompass.com. Retrieved 2018-11-07.
4. ^ "Columns - An Islander's offerings from Essex by James Marsh". Penguin-news.com. 2012-04-19. Archived from the original on 2014-10-16. Retrieved 2014-08-21.
5. ^ "Flying Frenchman takes off in 'overgrown pushchair' | St Helena Online". Sthelenaonline.org. 2012-10-23. Archived from the original on 2014-03-01. Retrieved 2014-08-21.
6. ^ "Police urging motorists to slow down". Suntci.com. 2009-07-15. Archived from the original on 2014-02-28. Retrieved 2014-08-21.
7. ^ "Modern Living: Think Metric". Time Magazine. 9 June 1975. Archived from the original on 22 January 2011. Retrieved 15 June 2010. Meanwhile, the metricization of America is already taking place. Individual federal agencies, school systems, states and industries, as well as radio announcers, supermarkets, beverage bottlers and ballpark scoreboards, are hastening the everyday use of meters, liters and grams. ...a road sign outside Fergus Falls reads, ST. CLOUD 100 MILES OR 161 KILOMETERS. Other signs note that 55 m.p.h. equals 88 kilometers per hour.
8. ^ "Our Traffic Problems Are Going To Get Worse". Samoa News. 2013-06-03. Archived from the original on 2013-09-14. Retrieved 2014-08-21.
9. ^ "Maila Halom". Guampdn.com. Retrieved 2014-08-21.
10. ^ [1] Archived March 1, 2014, at the Wayback Machine.
11. ^ Conor Foley (Staff Writer) (2011-07-06). "Cops: Teen was driving 75 mph in city rollover crash". Virgin Islands Daily News. Retrieved 2014-08-21.
12. ^ JOY BLACKBURN (Daily News Staff) (2012-08-24). "Weather to begin clearing up today as Isaac leaves area - News". Virgin Islands Daily News. Archived from the original on 2013-09-16. Retrieved 2014-08-21.
13. ^ "The Nassau Guardian". The Nassau Guardian. Archived from the original on 2014-02-26. Retrieved 2014-08-21.
14. ^ "Ideas and Opinions – Marijuana – another perspective - Amandala Newspaper". amandala.com.bz. Archived from the original on 18 September 2013. Retrieved 29 April 2018.
15. ^ "Gale warning issued, Apia town drowns". Samoaobserver.ws. 2013-02-02. Archived from the original on 2014-02-27. Retrieved 2014-08-21.
16. ^ Hunte, Owan. "Road Safety Guidelines For Visitors - Drive-A-Matic Car Rentals St. Lucia". www.drivestlucia.com. Retrieved 2018-10-29.
17. ^ Thursday, 21 August 2014 03:30:52 (AST) (2010-10-31). "St. Vincent appeals for aid as Tomas leaves 'millions and millions' in damage – I-Witness News". Iwnsvg.com. Archived from the original on 26 February 2014. Retrieved 2014-08-21.
18. ^ "Businesses Close Early Due to Passage of TS Isaac". The St. Kitts-Nevis Observer. 2012-08-22. Archived from the original on 2013-02-03. Retrieved 2014-08-21.
19. ^ "Another Metric System Fault". The New York Times. Associated Press. 1 November 2007. Archived from the original on 10 November 2012. Retrieved 1 November 2010.
20. ^ "A. Classes of Track". Rules Respecting Track Safety. Transport Canada. 3 November 2008. Archived from the original on 2012-08-25. Archived 25 August 2012.