An official indoor volleyball, under FIVB specifications, has a circumference of 65 to 67 centimeters and weighs between 260 and 280 grams, with an internal pressure of roughly 0.30 to 0.325 kilograms per square centimeter. The ball is built from a flexible leather or composite-leather outer shell over a rubber or rubber-composite bladder, deliberately designed to be light and slightly softer than a basketball or soccer ball, since players control it primarily with their bare forearms and open hands rather than with equipment.
Modern competition balls are typically constructed from panels in contrasting colors — often a mix of three colors rather than a single solid tone — specifically to help players track the ball's rotation and flight path more easily during fast play, a visual design choice credited with improving both passing accuracy and television visibility since its widespread adoption from the late twentieth century onward.
Indoor vs. beach balls
Beach volleyballs are built to broadly the same size and weight specification as indoor balls but are typically slightly larger, softer and lower-pressure, with a textured, non-absorbent cover designed to resist water and sand and to be easier to see and control outdoors in wind and bright sunlight.
Panel count and construction
Most modern competition volleyballs use either an eighteen-panel or similar multi-panel construction, curved and stitched or bonded together to approximate a true sphere as closely as possible; earlier volleyballs often used fewer, larger panels. A more perfectly spherical ball with consistent panel seams flies more predictably and is less prone to unwanted knuckling or erratic movement on a hard-driven hit, which is part of why manufacturers continue to refine panel shape and bonding technique even though the ball's basic size and weight specifications have stayed relatively stable for decades.
