Law 2 - The Ball

FIFA LAWS OF THE GAME

The ball is of a circumference of not more than 70 cm and not less than 68 cm

Law 2 - The Ball
Qualities and Measurements
The ball is:
spherical made
-of leather or other suitable material
-of a circumference of not more than 70 cm (28 ins) and not less than 68 cm (27 ins)
-not more than 450 g (16 oz) in weight and not less than 410 g (14 oz) at the start of the match
-of a pressure equal to 0.6 – 1.1 atmosphere (600 – 1100 g/cm2) at sea level (8.5 lbs/sq in 15.6 lbs/sq in)
Replacement of a Defective Ball

If the ball bursts or becomes defective during the course of a match:

the match is stopped
the match is restarted by dropping the replacement ball at the place where the first ball became defective
If the ball bursts or becomes defective whilst not in play at a kick-off, goal kick, corner kick, free kick, penalty kick or throw-in:

the match is restarted accordingly
The ball may not be changed during the match without the authority of the referee.