Football or futsal ball? Check more than size 4

A request for a “size 4 ball” can leave an important question unanswered: is it for youth football or for futsal? Both descriptions appear in shops, but the number alone does not identify the required ball. Start with the game and competition, then match the product to them.

This guide compares association football, also called soccer, with FIFA futsal. It uses the IFAB’s 2026/27 football laws and FIFA’s 2025–26 futsal laws. It does not certify a product, describe a ball we have tested or assume that every indoor football session follows FIFA futsal rules.

One size number, two product categories

The adidas ball-sizing guide places size 4 in its youth football range and also uses that number for futsal balls. Its age suggestions are manufacturer guidance, not a worldwide competition rule. A parent buying for a junior team and an adult joining futsal could therefore search for the same size and need different products.

Read beyond a shop’s size filter. Look for the stated game, full model name and specification. “Size 4” is not enough information to establish that a youth football is a futsal ball, or that a futsal ball is accepted by a particular junior football league.

Compare the actual rulebook measurements

IFAB Law 2 specifies the standard football’s circumference and its weight at the start of the match. FIFA’s futsal Law 2, on page 27, gives a different circumference range and its own starting-weight range.

Standard ball specifications in the cited rulebooks

Game	Around	Weight
Football	68–70 cm	410–450 g
Futsal	62–64 cm	400–440 g

“Around” means circumference, not width through the centre. The weight figures apply at the start of the match. These are the standard entries from those editions, not specifications for every youth variation or every product carrying a retail size label.

The ranges also explain why “a futsal ball is heavier than a football” is too broad. The listed weights overlap, while the futsal circumference is smaller. A comparison with a particular youth size 4 football is a different comparison from one with the standard football in this table.

Futsal’s rebound requirement is separate

The futsal rulebook specifies a first rebound between 50 and 65 centimetres after a drop from two metres. That is another property to check; matching circumference and weight alone does not establish compliance with the full specification.

Treat the rebound figure as part of the rulebook, not as a claim that we tested a pictured ball. A casual bounce beside a shop shelf is not proof of official approval. Nor should you assume that changing an ordinary football’s inflation turns it into a suitable futsal ball. Follow the product’s inflation instructions and the applicable competition requirements.

Let the organiser resolve the youth question

The IFAB’s general modifications allow the responsible football bodies to adjust ball size, weight and material for youth, veterans, disability and grassroots football. FIFA’s futsal book provides similar flexibility on page 11. Neither point gives an individual shopper permission to choose a different match ball unilaterally.

Ask the team or organiser to identify the format, age group and required ball before ordering. If the reply only says “size 4,” clarify whether it means a football or a futsal product. Give them the exact model rather than relying on a photograph whose markings cannot be read.

For example, imagine two otherwise similar online listings: one says youth football and the other says futsal. The shared number is not a reason to choose the cheaper one automatically. Resolve the intended use first, then compare suitable options. This is a shopping example, not an endorsement of a particular model.

Practical takeaway

Choose by game first, then check circumference, starting weight, any rebound requirement and the organiser’s rules. Keep the size label attached to its product category. Our basketball and 3x3 comparison shows another case where a familiar size label needs context.

When assembling the rest of the kit, treat footwear as its own decision. Our soccer-boot guide explains why playing surfaces matter; choosing a ball does not settle which boots a venue permits.