Football Ball Laws of the Game: Size, Weight, Pressure, FIFA Quality Marks and Defective-Ball Rules Answered

Law 2 of the IFAB Laws of the Game sets the specification for a match football: spherical, 68 to 70 cm in circumference, 410 to 450 g at the start of the match and 0.6 to 1.1 atmosphere at sea level. It also covers marked balls, defective balls and spares, rules that shape the stoppages read on RubiScore.

This Q&A follows the 2026/27 edition of the Laws, in force since 1 July 2026. IFAB's list of 2026/27 changes does not include Law 2. Event lists on match pages at https://rubiscore.com record goals, cards and substitutions by minute, which is the context for the data section near the end.

What does Law 2 say a match ball must be?

Law 2.1 lists five requirements. Every ball used in a match must be:

• Spherical.
• Made of suitable material. The Law names no specific material.
• 68 to 70 cm in circumference. That is 27 to 28 inches, or a diameter of roughly 21.6 to 22.3 cm.
• 410 to 450 g at the start of the match. That is 14 to 16 oz.
• 0.6 to 1.1 atmosphere at sea level. The Law also gives this as 600 to 1,100 g/cm² and as 8.5 to 15.6 lb/sq in.

The Law sets ranges, not single values. Two legal balls can differ by up to 40 g in weight and 2 cm in circumference. The weight rule applies at the start of the match, and Law 2 gives no weight figure for later.

Who decides which ball is used in a match?

The Laws set the specification and the competition sets the model. Law 2 names no brand or design. What it does say:

• FIFA and confederation competitions. Every ball must meet Law 2 and bear one of the marks of the FIFA Quality Programme for Footballs.
• National association competitions. These may require the same marks.
• Advertising. In official competitions, the ball may carry no commercial advertising except the competition's logo or emblem, the organiser's, and the authorised manufacturer's trademark.
• Changes during play. The ball may not be changed during the match without the referee's permission.

In practice, the organiser of a league or tournament picks its official ball, which is why different competitions use different balls inside the same Law 2 window.

What do the FIFA Quality marks mean?

They show that a ball has passed independent testing beyond the measurements in Law 2. The FIFA Quality Programme for Footballs began in 1996. Institutes approved by FIFA do the testing, and IFAB must approve the extra requirements behind each mark. The three marks are:

• FIFA Quality Pro. Emphasises first-class performance, accuracy and safety, for use at the highest level.
• FIFA Quality. Puts more weight on durability and safety than the entry mark, while still testing basic performance and accuracy.
• FIFA Basic. Sets minimum standards that stay affordable at every level. It replaces the International Match Standard (IMS) mark.

FIFA says a ball must pass seven tests to earn the FIFA Quality mark: weight, circumference, roundness, bounce, water absorption, loss of pressure, and shape and size retention. Quality Pro applies them under more demanding conditions. Balls tested to the earlier IMS standard remain eligible until their certification expires.

What happens if the ball becomes defective?

Play stops, the ball is replaced and the restart depends on what was happening. Law 2.2 sets out three cases:

• Ball in play. Play is stopped and restarted with a dropped ball.
• At a restart. If the ball becomes defective at a kick-off, goal kick, corner kick, free kick, penalty kick or throw-in, the restart is retaken.
• During a penalty kick or shoot-out. If the ball becomes defective as it moves forward and before it touches a player, the crossbar or a goalpost, the kick is retaken.

The dropped ball follows Law 8, and IFAB's own examples show the logic. If a ball bursts as a pass reaches a team-mate, the referee stops play, has the ball changed and drops it at the position where play stopped, for one player of the team that would have kept or gained possession. If it bursts inside the goal area after a shot passes the goalkeeper, without entering the goal, it is dropped for the defending goalkeeper, because play stopped inside that team's penalty area.

Can extra balls be kept around the pitch?

Yes. Law 2.3 allows additional balls that meet the Law 2 requirements to be placed around the field of play, and their use is under the referee's control. Spares meet the same measurements, so a replacement does not change the specification of the match.

A separate rule in Law 5 covers an extra ball that enters the field uninvited. The referee stops play, with a dropped ball restart, only if it interferes with play. Otherwise play continues and the ball is removed at the earliest opportunity.

Which ball sizes are used in youth football?

Law 2 describes "all balls" by measurements, and the numbered sizes 3, 4 and 5 are not terms used in it. IFAB's general modifications let national associations, confederations and FIFA change the size, weight and material of the ball for youth, veterans, disability and grassroots football, and set their own youth age limits.

Youth sizes are therefore decided nationally. England Football's published guidance, checked in October 2026, lists size 3 from under-7 to under-11, size 4 for under-12 and under-13, and size 5 from under-14 upwards. Other countries use different age bands, and associations revise theirs, so the current guidance of the relevant association applies.

How does the connected ball support offside decisions?

An inertial measurement unit (IMU) is a motion sensor. Placed in the centre of the ball, it reports the ball's movement 500 times per second, which helps officials find the exact moment of a kick. FIFA describes the system in its own material:

• 2022 men's World Cup. The ball, Al Rihla, carried an IMU feeding the video operation room. Twelve roof cameras tracked the ball and up to 29 data points per player, 50 times per second. When an attacker receives the ball after being offside at the moment a team-mate played it, the system alerts the video match officials, who check the automatically selected kick point and offside line before the referee is told.
• 2023 Women's World Cup. OCEAUNZ was the first Women's World Cup ball with the technology. FIFA said its sensor sends data to as many as 28 antennas around the pitch, and also yields shot speed, spin and shot distance.
• 2026 World Cup. FIFA's October 2025 announcement of the TRIONDA ball describes a 500Hz motion sensor chip sending data to the video assistant referee system in real time. FIFA's June 2026 preview added that clear positional offsides would go straight to the on-pitch officials, and that the system would not judge interference by offside players who never touch the ball.

The ball sensor is not part of goal-line technology. FIFA states that the World Cup 2026 goal-line system rests on 14 high-speed cameras and that sensor data plays no part in deciding whether the ball crossed the line. Law 5 lets competitions use such technology, so its use is a competition choice.

Why does the ball matter to match data?

Four links connect Law 2 to the numbers:

• Ball-in-play time. The match clock keeps running, but effective playing time counts only the periods when the ball is in play. Each replacement of a defective ball is a stoppage that lowers that figure, usually slightly when a spare is close at hand.
• Added time. Law 7 lists substitutions, injuries, time-wasting, disciplinary sanctions, VAR checks, goal celebrations and any other cause, including a significant delay to a restart. A long search for a replacement ball would fall under the last item. The Law sets no formula, so the amount is the referee's call.
• Event timestamps. Standard event lists cover goals, cards and substitutions by minute. A ball change is not among those entries, so it normally leaves no line. Injuries, VAR checks and substitutions are far more common causes of a pause, so a gap should not be read as a ball change without a source.
• Possession reads. A dropped ball gives the ball to the side judged entitled to it, so it is safer not to credit what follows as a recovery or a won duel.

A hypothetical example shows the effect. In Match X, the ball bursts in the 63rd minute while Team A attacks. A spare is brought on and the referee drops it for a Team A player where play stopped. Nothing is logged, so the only trace is a short pause with no recorded cause.

Timelines on platforms such as RubiScore show events by minute, which makes it possible to check whether a quiet stretch lines up with logged substitutions, injuries or VAR reviews before blaming a ball change. Sensor metrics such as shot speed were published by FIFA for specific tournaments and should not be assumed for an ordinary league match.

Which misconceptions come up most often?

• "Every match ball is the same." Law 2 allows a window of 40 g and 2 cm, and official balls differ by competition.
• "Size 5 is written into the Laws." Law 2 gives measurements only. Numbered sizes are labels used by manufacturers and associations.
• "A burst ball means a retake." A retake applies only when the ball fails at a restart or during a penalty kick. A ball in play restarts with a dropped ball.
• "The sensor in the ball decides goals." Goal-line technology is a separate system based on cameras.
• "The sensor rules on offside or handball by itself." For offside it supplies the kick point, and video officials validate the result. Interference by an offside player stays a referee judgement. The FIFA material reviewed here describes no handball function, and handball remains a judgement under Law 12.

Verdict

Law 2 is brief. It fixes the ball inside a narrow window, requires tested balls at the top level and tells the referee how to handle a ball that fails. Model choice and youth sizes are left to organisers and national associations, and sensors in the ball are a competition option. For data readers, a replaced ball is a small, rarely logged stoppage.