Volleyball ball size, weight and pressure: indoor, beach and youth balls compared

This article in other languages: Deutsch · Polski

Indoor and beach volleyballs look alike, but the rules make them two different balls. Here the official numbers stand side by side: size, weight, pressure in the units your pump shows, what size 5 and size 4 mean, which balls the organisers name for their competitions and how many balls are in play. All values come from the current rulebooks; every conversion is our own calculation.

Indoor, beach and youth ball side by side

The FIVB rulebooks define the ball in rule 3.1: a sphere with a bladder inside, a light colour or a combination of colours, plus circumference, weight and inside pressure.¹ The beach rulebook adds that the cover must not absorb moisture.³ The FIVB indoor rules set no ball for young players, so the third column shows one federation’s youth rule as an example: USA Volleyball’s 12-and-under competition at its Junior National Championships.⁴

All balls used in one match must be identical in circumference, weight, pressure, type and colour (rule 3.2 in both rulebooks). Before the match the first referee inspects the balls (rule 23.3.1.1); the second referee takes all match balls, checks that colour, circumference, weight and pressure are the same and keeps checking during the match (rule 24.2.9).¹⁷

Pressure in psi, bar and hPa

The rulebooks give the pressure in kg/cm², short for kilogram-force per square centimetre. If your gauge shows psi, bar or hPa, these are the factors: one kg/cm² is exactly 98,066.5 pascals, one psi is 6,894.757 pascals and one bar 100,000 pascals; a hectopascal (hPa) is the same as a millibar.² The limits, converted:

Inside pressure in hPa (= mbar): indoor and beach ball, lowest to highest allowed value

Indoor306

Beach196

hPa150200250300350

The FIVB prints its own conversions in brackets: 4.26 to 4.61 psi and 294.3 to 318.82 mbar indoors, 171 to 221 mbar on the beach.¹³ Our exact values differ from them by less than 0.5%, so both lead to the same result in practice: an indoor ball needs about 4.3–4.6 psi on the gauge, a beach ball about 2.5–3.2 psi.

Why the beach ball is bigger and softer

The beach rulebook names one reason itself: the cover must not soak up water, because matches can go on in the rain.³ For the larger size and the lower pressure it gives no reason, and we found no official explanation (no data). What the numbers show, taking the middle of each range: a beach ball is 1 cm larger around, has about 5% more volume at the same weight and is pumped to about 36% less pressure than an indoor ball (our calculation from the two rules 3.1).

At FIVB, world and official competitions both disciplines must use FIVB-approved balls.¹³ Everything else that changes on sand, from the block to the time for the serve, is on our page Indoor vs Beach Volleyball; the beach rules in plain words are on Beach Volleyball.

Size 5, size 4 and lighter balls for kids

The rulebooks never say “size 5”: they describe the ball by circumference and weight. Size 5 is a manufacturers’ label. The maker of the FIVB’s official game ball lists it as size 5 with 65 to 67 cm and 260 to 280 g, exactly the values of rule 3.1.⁵ Its size 4 junior ball is smaller and lighter: 62 to 64 cm and 240 to 260 g, according to the maker’s data sheet.⁶ In the middle of the ranges that is about 1 cm less in diameter and about 13% less volume than a size 5 (our calculation).

Which ball children play with is up to each federation. USA Volleyball’s 12-and-under competition at its Junior National Championships keeps the size and pressure of the adult ball but cuts the weight to 198–227 g (7 to 8 oz), about 21% lighter in the middle of the range.⁴ Lower nets and smaller courts for young players are on our rules page.

Which balls are used in competitions

Rule 3.2 says that FIVB, world and official competitions, and also national and league championships, must be played with FIVB-approved balls, unless the FIVB agrees otherwise.¹ We found no list of approved models published by the FIVB (no data). Which ball is used is announced by the organiser:

We name the models only because the organisers do. In your league, the competition regulations say which ball is used.

Three, four or five balls: the ball system

At FIVB, world and official indoor competitions five balls are in play, with six ball retrievers: one in each corner of the free zone and one behind each referee (rule 3.3).¹ The 2017–2020 rulebook already called this the “five-ball system”.¹¹ The refereeing guidelines explain the routine: the retrievers at positions 1, 2, 4 and 5 each hold a ball, the second referee gives the fifth ball to the server for the first and the deciding set, and between rallies the balls are rolled along the floor, never thrown.⁷

On the beach the FIVB uses four balls and six retrievers (beach rule 3.3).³ USA Volleyball recommends a three-ball system for its nationally sanctioned competitions (USAV 3.3).⁴ More terms from the rulebook are in our volleyball glossary.

Frequently asked questions

What is the correct pressure for an indoor volleyball?

FIVB rule 3.1 sets 0.30 to 0.325 kg/cm². That is 4.27–4.62 psi, 0.294–0.319 bar or 294–319 hPa.

Is a beach volleyball bigger than an indoor volleyball?

Slightly: 66 to 68 cm around instead of 65 to 67 cm, with the same weight of 260 to 280 g and a much lower pressure of 0.175 to 0.225 kg/cm² (2.49–3.20 psi).

What size volleyball do adults use?

Size 5: the maker of the FIVB game ball lists it as size 5, with the values of FIVB rule 3.1 (65 to 67 cm around, 260 to 280 g). Which ball youth competitions use is decided by each federation.

How many balls are used in a volleyball match?

Five at FIVB indoor competitions, with six ball retrievers, and four on the beach. USA Volleyball recommends a three-ball system for its nationally sanctioned competitions.