We actually had to look this up: The length of a football pitch must be between 100 yards (90m) and 130 yards (120m) and the width not less than 50 yards (45m) and not more than 100 yards (90m). The goal itself must be eight feet high (2.44m) and eight yards wide (7.32m).
A match in the top division of the women's soccer league in the United States pushed this to the very limit when they played on a pitch that measured just 100m by 58m, resulting in a game that bordered on the farcical, with the edges of the penalty areas almost touching the sidelines.
Western New York Flash and Seattle Reign played the game (with both sides featuring players from the US women's national team) on the Frontier Field in Rochester, New York - the home field of lower-league baseball team the Rochester Red Wings - on Saturday night. The Flash usually play their home games at Sahlen's Stadium, but the pitch had been booked for a festival which was headlined by nineties R&B group TLC. They were instructed not to use the baseball diamond, which resulted in a condensed field being hurriedly marked out.
Word spread quickly on Twitter about the ridiculous size of the pitch:
Why are they playing this game on a baseball field? That pitch is a joke. Far too small. #NWSL— Alan Bain (@bainalan05) July 9, 2016
US soccer legend Carli Lloyd also tweeted her disappointment during the game, but quickly deleted her comments in order that the event would not gain further attention; she retweeted a comment by Welsh international Jessica Fishlock which reads, "It's not about winning or losing ... It's about Respect. Tonight there was [none] & that's a Shame from such a good League."
The League were forced to issue a statement apologising for the decision to use the pitch for a professional game.
You can watch footage of the game, which finished 3-2 to The Flash, below.