A legal football field is measured by its lines.

How officials check the field

1. Confirm the field is rectangular and the touchlines are longer than the goal lines.
2. Check that the required markings are present: boundary lines, halfway line, centre mark and circle, goal areas, penalty areas, penalty marks, penalty arcs, corner arcs, and corner flagposts.
3. Check that the markings are clear, continuous, safe, and not wider than the law allows.
4. Check that goals, nets, corner flags, technical areas, and any competition technology are safe and correctly placed.
5. If something is missing, unsafe, or incorrectly marked, the referee follows the competition procedure, deals with safety first, and reports issues that cannot be fixed.

This page covers 11-a-side football

These dimensions are for association football under the Laws of the Game. Youth football, small-sided football, futsal, indoor football, beach soccer, school competitions, and local recreational formats can use different field sizes and markings. Professional competitions can also set tighter stadium requirements than the basic law.

There is a permitted range, not one universal size

For ordinary 11-a-side matches, the touchline length must be between 90 m and 120 m (100 to 130 yds). The goal line width must be between 45 m and 90 m (50 to 100 yds). The touchline must be longer than the goal line, so a square field is not legal.

For international matches, the permitted range is narrower: 100 m to 110 m (110 to 120 yds) long and 64 m to 75 m (70 to 80 yds) wide. A commonly used elite pitch size is 105 m by 68 m, but that is not the only legal size unless the competition requires it.

The lines are part of the areas they mark

The line is not neutral space. A ball touching the touchline or goal line is still in play because the line belongs to the field. A foul on the penalty-area line is treated as inside the penalty area because the line belongs to the penalty area. A player touching the penalty-area line at a penalty kick is inside the penalty area for encroachment purposes.

This same idea appears throughout football rules. It is why ball in and out of play and goal-line decisions use the whole-ball-over-the-whole-line test.

Field markings must be clear and safe

The field must be marked with continuous lines that are not dangerous. All lines must be the same width and may not be wider than 12 cm (5 ins). The goal lines must be the same width as the goalposts and crossbar, which matters for close goal-line judgments because the line and frame are part of the same measured boundary.

Only the football markings required by Law 1 should be used on the field for football. On artificial surfaces, other sport lines may be allowed if they are a different colour and clearly distinguishable from the football markings.

The halfway line and centre circle control restarts

The halfway line joins the midpoints of the two touchlines and divides the field into two halves. The centre mark sits at the midpoint of that line. Around it is the centre circle, with a radius of 9.15 m (10 yds).

The centre circle does not decide whether a kick-off is legal by itself, but it gives officials a visible distance guide. At kick-off, opponents must stay at least 9.15 m from the ball until it is in play.

The goal area is the smaller box

The goal area is marked from each goalpost 5.5 m (6 yds) along the goal line and 5.5 m into the field, then joined by a line parallel to the goal line. It is often called the six-yard box, but the legal measurement is taken from the inside of each goalpost.

The goal area matters most for goal kicks and for certain free-kick placements close to goal. It is also a useful visual reference for goalkeeper and restart situations, but it should not be confused with the larger penalty area.

The penalty area is the larger box

The penalty area is marked from each goalpost 16.5 m (18 yds) along the goal line and 16.5 m into the field, then joined by a line parallel to the goal line. A direct-free-kick offence by a defender inside this area normally becomes a penalty kick.

The penalty mark is 11 m (12 yds) from the midpoint between the goalposts. Outside the penalty area, the penalty arc marks 9.15 m (10 yds) from the penalty mark so officials can keep other players the required distance away at a penalty kick.

The corner arc decides legal corner placement

Each corner area is a quarter circle with a 1 m (1 yd) radius from the corner flagpost, drawn inside the field. For a corner kick, the ball must be placed in the corner area. Because the line belongs to the area, the ball can be on the arc line and still be legally placed.

Corner flagposts are required at each corner. They must be at least 1.5 m (5 ft) high, have a non-pointed top, and carry a flag. Optional halfway flagposts may be used outside the touchline.

The goals have fixed adult dimensions

A goal is placed at the centre of each goal line. The distance between the inside of the posts is 7.32 m (8 yds), and the distance from the ground to the lower edge of the crossbar is 2.44 m (8 ft). The posts and crossbar must be white, safe, firmly secured, and no wider or deeper than 12 cm (5 ins).

If the crossbar becomes displaced or broken and cannot be repaired or replaced correctly, the match cannot continue with a rope or flexible substitute. Safety and a proper goal frame come before continuing play.

Where measurements are taken from

Because the lines belong to the areas they mark, field measurements are taken from the outside of the lines. The penalty mark is measured from the centre of the mark to the back edge of the goal line. These details stop line width from changing the practical size of the field or the distance of a penalty kick.

Natural, artificial, and hybrid surfaces can be legal

The field may be natural grass, artificial turf if competition rules permit it, or a permitted hybrid system. Artificial surfaces used in higher-level representative or international club matches may need to satisfy the relevant FIFA Quality Programme requirements. Artificial football surfaces must be green.

Leagues can be stricter than the basic law

The Laws of the Game give the permitted ranges, but competitions can decide exact field dimensions, technical-area arrangements, advertising positions, goal-line technology use, VAR infrastructure, and local inspection procedures. That is why two legal pitches can look slightly different while still using the same football laws.

If a field is safe but imperfect at a lower level, the referee may be able to let the match go ahead under local competition guidance and report the problem. If the issue creates danger or makes the match unplayable, the referee should not ignore it.

Misunderstandings to avoid

• "Every field has to be 105 by 68 metres" is wrong. That is common at elite level, but the laws allow a range unless the competition sets a specific size.
• "The line is outside the area" is wrong. Lines belong to the areas they mark.
• "A ball on the line is out" is wrong. The whole ball must wholly cross the whole boundary line.
• "The six-yard box is measured from the edge of the post" is too loose. Law 1 measures the goal area from the inside of each goalpost.
• "Extra markings are harmless" is not always true. Unauthorized or confusing marks can affect decisions and may have to be removed or reported.

Source material

• IFAB Law 1 - The Field of Play
• IFAB Law 9 - The Ball in and out of Play
• IFAB Law 14 - The Penalty Kick
• IFAB Laws of the Game