Tennis Court Dimensions: Singles vs Doubles in Feet

A standard tennis court measures 78 feet (23.77 meters) from baseline to baseline. The court is 27 feet (8.23 m) wide for singles and 36 feet (10.97 m) wide for doubles. The extra width in doubles comes from two outside alleys, each 4.5 feet wide. Those measurements are the official playing lines, not the total land area needed for safe movement around the court.

These are the dimensions defined in the International Tennis Federation’s court overview and the 2026 tennis rules. Whether you watch Wimbledon, play at a local park or help mark a court, this layout is the starting point.

Tennis court dimensions: singles vs doubles

The two court widths apply to different kinds of play, but the 78-foot length stays the same. One physical court can serve both singles and doubles because the inner singles sidelines remain visible inside the wider doubles sidelines.

Why is a doubles tennis court wider?

In doubles, two players defend each side, so the legal target area expands sideways. The extra space is called the doubles alley, or tramline in some regions. It measures 4.5 feet from the singles sideline to the doubles sideline on each side. Add the two alleys to 27 feet and you get the 36-foot doubles width.

During standard singles play on a marked doubles court, those outside strips are out for most rallies. When a doubles pair plays, balls landing on the alley line or inside it can be in. A player does not need to stand inside the singles area: court boundaries specify where the ball may land, not where every player must remain during a rally.

How big is a tennis service box?

The service line is drawn 21 feet from the net on each half. A center service line divides the space between the two singles sidelines into left and right service courts. Each box is therefore approximately 21 feet long and 13.5 feet wide, measured to the relevant boundaries.

A legal serve must cross the net and land in the diagonally opposite service box. The line counts as part of the box, so a serve touching that boundary is in if it otherwise complies with the rules. Learn why a second failed serve costs the point in our tennis terms and definitions guide.

What is the distance between service line and baseline?

Each half of the court is 39 feet long. Subtract the 21-foot distance from net to service line and the zone behind that line extends 18 feet to the baseline. This backcourt is where many baseline rallies unfold. The baseline is not the edge of the entire facility: players need additional space behind it to run and stop safely.

How high is a tennis net?

A regulation net stands 3 feet at its center, where a strap holds it down, and 3 feet 6 inches at the posts. The net is therefore slightly lower at midcourt. For singles played with a full doubles net, the rules provide for singles sticks to support the required configuration. Net-post placement depends on singles and doubles use.

A net that sags far below regulation height or is pulled too tight at the center can change the difficulty of passing shots. For competition, the net should be checked according to the appropriate governing rules rather than judged only by appearance.

Are grass, clay and hard courts different sizes?

No. Standard adult singles and doubles line dimensions are the same regardless of whether the surface is grass, clay or a hard court. The surface affects bounce, traction, maintenance and playing style, but it does not change a 78-foot baseline-to-baseline measurement.

Some facilities color the singles alleys differently or mark youth formats on the same surface. That is a visual choice or a modified competition, not a new standard singles width. Officials use the lines designated for the match.

How much space is needed to build a tennis court?

The playing rectangle alone is not enough. Players need run-off space beyond every sideline and baseline, and a fence should not sit immediately against the legal boundary. Tournament standards can be much larger than the 78-by-36-foot court itself. For example, WTA tournament standards specify substantial clearance behind baselines and beyond doubles sidelines.

If you are measuring a backyard or community-site project, ask the local court builder and sports association for the intended level of play, run-off dimensions, drainage, slope, lighting and accessibility requirements. Do not multiply the official court dimensions and assume that resulting square footage is a safe construction footprint.

How do tennis court lines work?

Baselines and sidelines

The baselines are the short lines behind each player’s end of the court. The singles sidelines create the narrower playing area; the doubles sidelines are the outer long boundaries. A ball that touches a valid line on its first bounce is in, even if most of the ball’s mark lies outside it.

Center mark and service lines

A short center mark divides each baseline visually for service positions. The center service line runs between the service lines across the service area, perpendicular to the net. These markings help distinguish the correct diagonal service box from the rest of the court.

New players sometimes mistake the center service line for a second singles boundary. It is only part of the service-court layout, not an additional sideline during a rally. For the scoring side of serving and games, see our tennis scoring explainer.

Are junior tennis courts the same size?

Not always. The ITF’s rules allow smaller court formats for 10-and-under competition, commonly identified by red and orange stages, alongside correspondingly age-appropriate balls. Those layouts develop stroke control and court coverage gradually. Ask the event organizer which junior format is in use before laying tape or booking a court.

Tennis court dimensions FAQ

How wide is a tennis court for singles?

27 feet (8.23 meters) between the singles sidelines.

How wide is a tennis court for doubles?

36 feet (10.97 meters), including both outer alleys.

Are tennis courts 78 feet or 84 feet long?

The official standard playing court is 78 feet long. Extra space behind the baselines is separate from that length.

How wide is a doubles alley?

Each is 4.5 feet. Together the two alleys add 9 feet to the singles width.

Is a ball that touches the line in?

Yes, provided it is the boundary line applicable to the point and the ball’s first bounce touches that line.

Measurements checked October 11, 2026 against the ITF court specification and current ATP/WTA competition materials. Local facility and youth competition rules can impose additional requirements.