Tennis · Laws of Tennis
Law 1: The Court
1 parts · 4 tests · 40 facts · updated 12 October 2026 · markdown
Law 1 of the Laws of Tennis defines the court and the net. The court is a rectangle 78 feet (23.77 m) long for both singles and doubles. Singles uses the inner court, 27 feet (8.23 m) between the singles sidelines, while doubles adds a strip of 4½ feet on each side for a width of 36 feet (10.97 m).
The net cord runs over the posts at 3½ feet (1.07 m), and a white strap holds the net down to 3 feet (0.914 m) in the middle, so it dips by half a foot towards the centre. Each post stands with its centre 3 feet beyond the doubles sideline and may be no more than 6 inches (15 cm) square or in diameter. When a doubles net is used for singles, singles sticks of at most 3 inches (7.5 cm) raise it to 3½ feet just outside the singles court. A serviceline runs 21 feet (6.40 m) from the net on each side, the centre serviceline splits the area into two equal service courts, and a 4-inch mark halves each baseline. Most lines are 1 to 2 inches wide, but baselines may be up to 4 inches, and every measurement is taken to the outside of the lines, so the lines are part of the court.
The facts below cover the court and net dimensions, posts and singles sticks, the lines, how a court is marked out and the space recommended around it.
1.11The Court
The size of the court, the net and its posts, the singles sticks, the lines, and the marking out of a court and the space around it.
Test 1Court size and the netTake a test
The court is a rectangle 78 feet (23.77 m) long, for singles and doubles alike.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
Singles uses the inner court, 27 feet (8.23 m) between the singles sidelines.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
Doubles adds a strip of 4½ feet on each side, making 36 feet (10.97 m).
Source: ITF Rules of Tennis 2026, Rule 1 · recall
A strap holds the net down to 3 feet (0.914 m) in the middle.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
The cord runs over the posts at 3½ feet (1.07 m), so the net dips by half a foot towards the centre.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
Both the strap and the band that covers the cord are entirely white.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
The net fills the whole space between the posts, with a mesh no ball can get through.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
21 feet, 27 feet, 36 feet and 78 feet.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
At most 1/3 inch (0.8 cm), at most 2 inches (5 cm), and 3 feet (0.914 m).
Source: ITF Rules of Tennis 2026, Rule 1 · recall
The net is 3½ feet at the posts and is held down to 3 feet at the centre.
Source: ITF Rules of Tennis 2026, Rule 1 · applied
Test 2Net posts and singles sticksTake a test
Each post stands with its centre 3 feet beyond the doubles sideline.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
Singles sticks raise the doubles net to 3½ feet just outside the singles court.
Source: ITF Rules of Tennis 2026, Rule 1 · applied
Like the posts in doubles, the sticks stand 3 feet outside the court being used.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
A net post may be no more than 6 inches (15 cm) square or 6 inches in diameter.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
A singles stick is half the width of a net post at most: 3 inches (7.5 cm).
Source: ITF Rules of Tennis 2026, Rule 1 · recall
Posts and sticks may stand at most 1 inch (2.5 cm) above the cord.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
A singles-only court takes a 33-foot (10 m) net between posts set outside the singles court.
Source: ITF Rules of Tennis 2026, Appendix X · recall
13 ft 6 in, 16 ft 6 in, 18 ft and 21 ft from the centre of the net.
Source: ITF Rules of Tennis 2026, Appendix X · recall
With the net hung, a singles stick goes in outside each singles sideline; the net is then raised to 3½ feet at the sticks and the centre strap holds it at 3 feet in the middle.
Source: ITF Rules of Tennis 2026, Rule 1 · applied
From the centre: A the singles sideline, B the singles stick, C the doubles sideline, D the net post.
Source: ITF Rules of Tennis 2026, Appendix X · applied
Test 3The lines of the courtTake a test
The end lines are the baselines and the side lines are the sidelines.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
A serviceline runs parallel to the net, 21 feet (6.40 m) from it on each side.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
The servicelines stop at the singles sidelines, so the service courts are singles-width.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
The centre serviceline runs midway between the singles sidelines, creating two equal service courts.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
A 4-inch (10 cm) mark, drawn inside the court, halves each baseline.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
Most lines are 1 to 2 inches wide, but baselines may be up to 4 inches (10 cm).
Source: ITF Rules of Tennis 2026, Rule 1 · recall
These two lines are fixed at 2 inches (5 cm); the others may be between 1 and 2 inches.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
The serviceline is 21 feet from the net and the baseline 39 feet.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
Service courts lie between the net and the serviceline; the baseline closes the court.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
A is a baseline, B a service line, C the centre service line and D a singles sideline.
Source: ITF Rules of Tennis 2026, Rule 1 · applied
Test 4Marking out and the space around the courtTake a test
Every measurement is taken to the outside of the lines, so the lines are part of the court.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
All lines are the same colour and must stand out clearly from the court surface.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
Besides the full court, the Red and Orange courts of Appendix VIII may be used for 10-and-under events.
Source: ITF Rules of Tennis 2026, Rule 1 · recall
The guide for international competition is 21 feet behind each baseline.
Source: ITF Rules of Tennis 2026, Appendix X · recall
Club courts are guided to 18 feet behind each baseline.
Source: ITF Rules of Tennis 2026, Appendix X · recall
The guide is 29.6 feet (9 m) of clear height above the net.
Source: ITF Rules of Tennis 2026, Appendix X · recall
Blended lines stay in the surface's colour family, a little lighter, and slightly narrower than standard lines.
Source: ITF Rules of Tennis 2026, Appendix X · recall
10 feet, 12 feet, 18 feet and 21 feet.
Source: ITF Rules of Tennis 2026, Appendix X · recall
The net line comes first, the corners are found from it, the baseline is checked, then the inner lines are marked.
Source: ITF Rules of Tennis 2026, Appendix X · applied
For club and recreational play the guide is 18 feet between the baseline and the backstop.
Source: ITF Rules of Tennis 2026, Appendix X · applied
Questions people ask
- How big is a tennis court?
- A tennis court is 78 feet (23.77 m) long. It is 27 feet (8.23 m) wide for singles and 36 feet (10.97 m) wide for doubles.
- How high is a tennis net?
- The net is 3½ feet (1.07 m) high at the posts and is held down to 3 feet (0.914 m) at the centre by a white strap.
- What are singles sticks used for?
- Singles sticks raise a doubles net to 3½ feet just outside the singles court, so it can be used for singles. They stand 3 feet outside the singles sideline and are at most 3 inches (7.5 cm) wide.
- Are the lines part of a tennis court?
- Yes. Every measurement is taken to the outside of the lines, so the lines are part of the court.
- How far is the service line from the net?
- Each serviceline runs parallel to the net, 21 feet (6.40 m) from it. The baseline is 39 feet from the net.
- How wide can the lines on a tennis court be?
- Most lines are between 1 and 2 inches wide, but the baselines may be up to 4 inches (10 cm). All lines are the same colour and must stand out clearly from the surface.
- How much space should there be behind the baseline?
- The guide for international competition is 21 feet behind each baseline, and for club and recreational courts it is 18 feet. The recommended clear height above the net is 29.6 feet (9 m).
Sources
ITF Rules of Tennis 2026, Rule 1 with Appendices IX and X (paraphrased in original wording; original questions authored from the Rules, not reproduced)
- ITF Rules of Tennis 2026, Rule 130
- ITF Rules of Tennis 2026, Appendix X10