A standard tennis court is 23.77 m (78 ft) long. It is 8.23 m (27 ft) wide for singles and 10.97 m (36 ft) wide for doubles, with a doubles alley of 1.37 m (4.5 ft) on each side. The net is 0.914 m (3 ft) high at the center and 1.07 m (3 ft 6 in) high at the posts. The service lines are 6.40 m (21 ft) from the net on each side. These playing dimensions are the same on every surface, whether hard court, clay, grass or carpet. This guide lists every official measurement, explains the lines and markings, covers the net and posts, recommended space around the court, junior court sizes, how to mark or check a court and common mistakes.
Rulebook note: Court dimensions and equipment specifications come from the ITF Rules of Tennis and its appendices, which also give guidance on run-off space. National federations such as the USTA publish construction and youth tennis guidelines, and facility requirements for particular competitions can be stricter. Check current ITF and national guidance when building or certifying a court.
Official court measurements
| Feature | Metric | Imperial |
|---|---|---|
| Court length | 23.77 m | 78 ft |
| Singles width | 8.23 m | 27 ft |
| Doubles width | 10.97 m | 36 ft |
| Doubles alley, each side | 1.37 m | 4.5 ft |
| Net to service line | 6.40 m | 21 ft |
| Service line to baseline | 5.49 m | 18 ft |
| Service box | 6.40 m x 4.115 m | 21 ft x 13.5 ft |
| Net height at center | 0.914 m | 3 ft |
| Net height at posts | 1.07 m | 3 ft 6 in |
| Center mark | 10 cm long, 5 cm wide | About 4 in by 2 in |
Lines and markings
The baselines are the lines at each end of the court. The sidelines run along the sides, with the inner lines marking the singles court and the outer lines marking the doubles court. The service lines run parallel to the net, 6.40 m from it, and the center service line divides the area between the service lines and the net into two service boxes on each side. A short center mark on each baseline shows where the server’s side of the court is divided. Under the ITF rules, most lines are between 2.5 cm and 5 cm wide, while the baselines may be up to 10 cm wide. All line measurements are taken to the outside of the lines, and the lines are part of the court, so a ball touching any part of a line is in.
The net and posts
The net stretches across the full width of the court and is held by a cord or metal cable over the tops of two posts. For doubles, the net posts sit 0.914 m (3 ft) outside the doubles sidelines. When a doubles court with a doubles net is used for singles, singles sticks are placed 0.914 m (3 ft) outside each singles sideline to raise the net to 1.07 m at those points. The net is held down at the center by a strap, which keeps the center height at 0.914 m. A white band covers the cord at the top of the net. Checking net height regularly matters, because a sagging or overly tight net changes how the court plays.
Space around the court
The playing lines are only part of the space a court needs. Players regularly run behind the baseline and outside the sidelines, so run-off space is important for safety and quality of play. ITF guidance recommends at least about 5.48 m (18 ft) behind each baseline and 3.05 m (10 ft) beside each sideline for recreational and club play, and about 6.40 m (21 ft) and 3.66 m (12 ft) for international-level play. Many high-level venues provide more. Based on these figures, a single court area typically ranges from about 34.75 m by 17.07 m (114 ft by 56 ft) to 36.57 m by 18.29 m (120 ft by 60 ft) or more.
Junior and modified courts
| Court | Typical length | Typical width | Ball |
|---|---|---|---|
| Red | About 11 to 12.8 m (36 to 42 ft) | About 5.5 to 6.1 m (18 to 20 ft) | Red, slowest |
| Orange | About 18 m (60 ft) | About 6.5 to 8.23 m (21 to 27 ft) | Orange |
| Green | 23.77 m (78 ft) | Full court | Green dot |
Red courts are often created across a full court, with several small courts fitting on one standard court using temporary lines and low nets. Orange courts often fit within a full court by using lines placed inside the baselines. Exact sizes vary by federation guidelines, so check your national youth tennis recommendations.
Court surfaces
Tennis is played on several surfaces, including acrylic hard courts, clay, grass, artificial grass and carpet. The dimensions do not change, but the surface affects ball speed and bounce. The ITF classifies surfaces by court pace, from slow to fast, based on testing. Clay is generally slower with a higher bounce, grass is generally faster with a lower bounce and hard courts vary. Line materials also differ, such as painted lines on hard courts and tapes or painted lines on clay.
Step-by-step: checking or marking a court
- Establish the net line across the middle of the court.
- Mark the baselines 11.885 m (39 ft) from the net on each side.
- Mark the doubles sidelines 10.97 m (36 ft) apart.
- Mark the singles sidelines 1.37 m (4.5 ft) inside the doubles sidelines.
- Mark the service lines 6.40 m (21 ft) from the net.
- Mark the center service line halfway between the singles sidelines.
- Add the center marks on each baseline.
- Check the diagonals of the doubles court, which should be equal, to confirm the court is square.
- Set the net height at 0.914 m in the center and 1.07 m at the posts.
Checking net height before play
Net height is one of the easiest things to get wrong on public and club courts. A simple check is to measure at the center strap, which should be 0.914 m (3 ft). Some players use a measuring stick or a marked racquet length for a quick estimate, but a tape measure is more accurate. Adjust the center strap or the tension crank at the post if needed. On a doubles net used for singles, insert singles sticks to raise the net correctly at the singles sidelines.
Why the dimensions matter
Consistent dimensions make the game fair and let players train on one court and compete on another without adjusting. The court shape also shapes tactics. The net is lower in the center, so crosscourt shots over the middle have more margin. The longer diagonal crosscourt gives more distance to work with than down the line. The doubles alleys add width, which changes angles and positioning in doubles.
Common mistakes
- Measuring to the inside of lines instead of the outside.
- Forgetting singles sticks on a doubles net.
- Leaving the net too high or low at the center.
- Too little run-off space behind the baseline.
- Confusing singles and doubles sidelines.
- Assuming junior courts have one fixed size everywhere.
- Not checking that the court is square.
Frequently asked questions
How big is a tennis court?
A tennis court is 23.77 m (78 ft) long, 8.23 m (27 ft) wide for singles and 10.97 m (36 ft) wide for doubles.
How high is a tennis net?
The net is 0.914 m (3 ft) high at the center and 1.07 m (3 ft 6 in) at the posts.
How much space is needed for a tennis court?
Including run-off space, a single court typically needs roughly 34.75 m by 17.07 m (114 ft by 56 ft) for recreational play, and more for higher-level play.
