Question: what is the standard size of a volleyball?
Answer: Internal pressure of these balls are set at 4.3 psi or 0.30-kgf-per-centimeter-squared. The adult indoor volleyball ball is 65 to 67-centimeters or 25.5 to 26.5-inches in circumference. They weigh 9.2 to 9.9-ounces or 260 to 280-grams. They have a psi of 4.3 to 4.6, or 0.3 to 0.325-kgf-per-centimeter-squared.