According to the second law of association football the ball has to:
- be a sphere filled with air
- have a circumference of 68–70 cm (27–28 in)
- weight about 410–450 g (14–16 oz)
- be inflated to a pressure of 0.6 to 1.1 atmospheres (59–108 kPa or 8.6–15.7 psi)
Most modern footballs are stitched from 32 panels of waterproofed leather or plastic (12 regular pentagons and 20 regular hexagons).