Miles per hour (mph, m.p.h., MPH, or mi/h) is a British imperial and United States customary unit of

speed In kinematics, the speed (commonly referred to as ''v'') of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a non-negative scalar quantity. Intro ...

expressing the number of

mile The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a imperial unit, British imperial unit and United States customary unit of length; both are based on the older English unit of Unit of length, le ...

s travelled in one

hour An hour (symbol: h; also abbreviated hr) is a unit of time historically reckoned as of a day and defined contemporarily as exactly 3,600 seconds ( SI). There are 60 minutes in an hour, and 24 hours in a day. The hour was initially establis ...

. It is used in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

, the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, and a number of smaller countries, most of which are UK or US territories, or have close historical ties with the UK or US.

Usage

World Map of Speed Limit Units on Traffic Signs

Road traffic

Speed limits and road traffic speeds are given in miles per hour in the following jurisdictions: *

Antigua and Barbuda Antigua and Barbuda is a Sovereign state, sovereign archipelagic country composed of Antigua, Barbuda, and List of islands of Antigua and Barbuda, numerous other small islands. Antigua and Barbuda has a total area of 440 km2 (170 sq mi), ...

Bahamas The Bahamas, officially the Commonwealth of The Bahamas, is an archipelagic and island country within the Lucayan Archipelago of the Atlantic Ocean. It contains 97 per cent of the archipelago's land area and 88 per cent of its population. ...

Belize Belize is a country on the north-eastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a maritime boundary with Honduras to the southeast. P ...

Dominica Dominica, officially the Commonwealth of Dominica, is an island country in the Caribbean. It is part of the Windward Islands chain in the Lesser Antilles archipelago in the Caribbean Sea. The capital, Roseau, is located on the western side of t ...

Grenada Grenada is an island country of the West Indies in the eastern Caribbean Sea. The southernmost of the Windward Islands, Grenada is directly south of Saint Vincent and the Grenadines and about north of Trinidad and Tobago, Trinidad and the So ...

Liberia Liberia, officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to Guinea–Liberia border, its north, Ivory Coast to Ivory Coast–Lib ...

(occasionally) *

Marshall Islands The Marshall Islands, officially the Republic of the Marshall Islands, is an island country west of the International Date Line and north of the equator in the Micronesia region of the Northwestern Pacific Ocean. The territory consists of 29 c ...

* Micronesia *

Palau Palau, officially the Republic of Palau, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands ...

Saint Kitts and Nevis Saint Kitts and Nevis, officially the Federation of Saint Christopher (St Kitts) and Nevis, is an island country consisting of the two islands of Saint Kitts and Nevis, both located in the West Indies, in the Leeward Islands chain of the Less ...

Saint Lucia Saint Lucia is an island country of the West Indies in the eastern Caribbean. Part of the Windward Islands of the Lesser Antilles, it is located north/northeast of the island of Saint Vincent (Saint Vincent and the Grenadines), Saint Vincent ...

* Saint Vincent and the Grenadines *

*The following

British Overseas Territories The British Overseas Territories (BOTs) or alternatively referred to as the United Kingdom Overseas Territories (UKOTs) are the fourteen dependent territory, territories with a constitutional and historical link with the United Kingdom that, ...

: **

Anguilla Anguilla is a British Overseas Territories, British Overseas Territory in the Caribbean. It is one of the most northerly of the Leeward Islands in the Lesser Antilles, lying east of Puerto Rico and the Virgin Islands and directly north of Sa ...

British Virgin Islands The British Virgin Islands (BVI), officially the Virgin Islands, are a British Overseas Territories, British Overseas Territory in the Caribbean, to the east of Puerto Rico and the United States Virgin Islands, US Virgin Islands and north-west ...

** British Indian Ocean Territory **

Cayman Islands The Cayman Islands () is a self-governing British Overseas Territories, British Overseas Territory, and the largest by population. The territory comprises the three islands of Grand Cayman, Cayman Brac and Little Cayman, which are located so ...

Falkland Islands The Falkland Islands (; ), commonly referred to as The Falklands, is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and from Cape Dub ...

Montserrat Montserrat ( , ) is a British Overseas Territories, British Overseas Territory in the Caribbean. It is part of the Leeward Islands, the northern portion of the Lesser Antilles chain of the West Indies. Montserrat is about long and wide, wit ...

Saint Helena, Ascension and Tristan da Cunha Saint Helena, Ascension and Tristan da Cunha is a British Overseas Territories, British Overseas Territory located in the Atlantic Ocean, South Atlantic and consisting of the island of Saint Helena, Ascension Island, and the archipelago of Tri ...

Turks and Caicos Islands The Turks and Caicos Islands (abbreviated TCI; and ) are a British Overseas Territory consisting of the larger Caicos Islands and smaller Turks Islands, two groups of tropical islands in the Lucayan Archipelago of the Atlantic Ocean and no ...

*The

Crown dependencies The Crown Dependencies are three dependent territory, offshore island territories in the British Islands that are self-governing possessions of the The Crown, British Crown: the Bailiwick of Guernsey and the Jersey, Bailiwick of Jersey, both lo ...

: **

Bailiwick of Guernsey The Bailiwick of Guernsey (; Guernésiais: ''Bailliage dé Guernési'') is a self-governing British Crown Dependencies, Crown Dependency off the coast of Normandy, France, comprising several of the Channel Islands. It has a total land area of ...

Isle of Man The Isle of Man ( , also ), or Mann ( ), is a self-governing British Crown Dependency in the Irish Sea, between Great Britain and Ireland. As head of state, Charles III holds the title Lord of Mann and is represented by a Lieutenant Govern ...

Jersey Jersey ( ; ), officially the Bailiwick of Jersey, is an autonomous and self-governing island territory of the British Islands. Although as a British Crown Dependency it is not a sovereign state, it has its own distinguishing civil and gov ...

*The following United States overseas dependencies: **

American Samoa American Samoa is an Territories of the United States, unincorporated and unorganized territory of the United States located in the Polynesia region of the Pacific Ocean, South Pacific Ocean. Centered on , it is southeast of the island count ...

Guam Guam ( ; ) is an island that is an Territories of the United States, organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. Guam's capital is Hagåtña, Guam, Hagåtña, and the most ...

Northern Mariana Islands The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands (CNMI), is an Territories of the United States, unincorporated territory and Commonwealth (U.S. insular area), commonwealth of the United States consistin ...

Puerto Rico ; abbreviated PR), officially the Commonwealth of Puerto Rico, is a Government of Puerto Rico, self-governing Caribbean Geography of Puerto Rico, archipelago and island organized as an Territories of the United States, unincorporated territo ...

United States Virgin Islands The United States Virgin Islands, officially the Virgin Islands of the United States, are a group of Caribbean islands and a territory of the United States. The islands are geographically part of the Virgin Islands archipelago and are located ...

Rail networks

Miles per hour is the unit used on the US, Canadian and Irish rail systems. Archived 25 August 2012. Miles per hour is also used on British rail systems, excluding trams, some light metro systems, the

Channel Tunnel The Channel Tunnel (), sometimes referred to by the Portmanteau, portmanteau Chunnel, is a undersea railway tunnel, opened in 1994, that connects Folkestone (Kent, England) with Coquelles (Pas-de-Calais, France) beneath the English Channel at ...

and

High Speed 1 High Speed 1 (HS1), officially the Channel Tunnel Rail Link (CTRL), is a high-speed railway linking London with the Channel Tunnel. It is part of the line carrying international passenger traffic between the United Kingdom and mainland Euro ...

Nautical and aeronautical usage

Nautical and aeronautical applications favour the

knot A knot is an intentional complication in Rope, cordage which may be practical or decorative, or both. Practical knots are classified by function, including List of hitch knots, hitches, List of bend knots, bends, List of loop knots, loop knots, ...

as a common unit of speed. (One knot is one

nautical mile A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude at t ...

per hour, with a nautical mile being exactly 1,852 metres 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 Cricket is a Bat-and-ball games, bat-and-ball game played between two Sports team, teams of eleven players on a cricket field, field, at the centre of which is a cricket pitch, pitch with a wicket at each end, each comprising two Bail (cr ...

tennis Tennis is a List of racket sports, racket sport that is played either individually against a single opponent (singles (tennis), singles) or between two teams of two players each (doubles (tennis), doubles). Each player uses a tennis racket st ...

and

baseball Baseball is a bat-and-ball games, bat-and-ball sport played between two team sport, teams of nine players each, taking turns batting (baseball), batting and Fielding (baseball), fielding. The game occurs over the course of several Pitch ...

Conversions

References

{{United States Customary Units Units of velocity Imperial units Customary units of measurement in the United States