Grass court lines are easy to overlook until a close call changes a point. On a fast, low-bouncing court, a ball that clips a painted stripe can be hard to judge, and worn grass near the baseline can make the markings look less clear than they do on television.
Knowing what each line marks—and how grass courts are maintained—helps you follow the score, make better calls and understand why the surface can play differently from one part of the court to another. Here’s a practical guide to the markings you’ll see at a club or tournament.
What the Lines on a Grass Tennis Court Mark
The layout is the same on grass as on other standard tennis courts. The white lines mark the court’s boundaries and service areas. A ball touching any part of a line is considered in if that line is part of the area being played.
- Baselines: The lines at each end of the court. Players serve from behind the baseline and rally within it.
- Singles sidelines: The inner side boundaries for singles matches.
- Doubles sidelines: The wider outer boundaries used in doubles. The strip between the singles and doubles sidelines is called the alley.
- Service lines: The lines across the court that mark the far edge of the service boxes.
- Center service line: The line that divides each side’s service area into left and right boxes.
- Center mark: A short mark at the middle of each baseline. It helps players line up correctly when serving from either side.
The net divides the court in half, but it is not a painted court line. During a serve, the ball must land in the diagonally opposite service box. During a rally, singles players use the inner sidelines, while doubles players use the outer ones.
Grass Court Dimensions and Line Width
Grass courts follow the standard tennis dimensions. The court is 78 feet long. It is 27 feet wide for singles and 36 feet wide for doubles. The service lines are 21 feet from the net on each side, creating service boxes that are 21 feet long and 13.5 feet wide.
| Marking or area | Standard measurement | What it means |
|---|---|---|
| Court length | 78 feet | Distance between the baselines |
| Singles court width | 27 feet | Distance between the singles sidelines |
| Doubles court width | 36 feet | Distance between the doubles sidelines |
| Service line from net | 21 feet | Marks the far end of each service box |
| Most court lines | 1–2 inches wide | Includes sidelines and service lines |
| Baseline | Up to 4 inches wide | May be wider than other lines |
For official court measurements, the lines count as part of the areas they mark. That is why a ball landing on the singles sideline is in during singles, and a ball landing in the alley is in during doubles but out during singles.
How Grass Court Lines Are Marked
Grass courts are usually marked with white paint suited to natural turf. The exact product and method can vary by venue, but the lines need to be clear without creating a surface that is dangerously slippery or damaging the grass. At smaller clubs, markings may need regular touch-ups as the court is used and the turf is mown.
Grass wears most quickly where players repeatedly start, stop and change direction. The baseline and the area just behind it can become especially worn, while the service boxes may see less foot traffic. When grass thins or the surface becomes uneven beside a line, the edge can be harder to read. A fresh, sharply marked court is easier to judge than one near the end of a busy playing period.
For players, a practical tip is to watch the ball’s landing point rather than the color or condition of the turf around it. If you are unsure on a recreational court, agree before the match on how to handle close calls. In friendly play, calling the ball out only when you are sure is usually fairer than guessing.
Why Line Calls Can Feel Different on Grass
Grass tends to produce a lower, less predictable bounce than a well-maintained hard court. That can make a ball’s landing and bounce harder to track, especially when a rally is moving quickly. A serve that skids close to the service line may seem to arrive before you have a clear view of where it landed.
There is also a tactical reason grass-court players pay close attention to the lines. A serve placed near the edge of a service box can pull a returner wide or jam them on the next shot. On the baseline, a deep ball close to the line can push an opponent back, while a shorter ball may invite them forward. Players often aim with a margin rather than trying to land every shot exactly on a stripe; the grass and the pace of the rally leave little time to recover from a miss.
At major events, electronic line-calling systems may assist with close decisions, depending on the tournament and court. At local clubs, players usually make calls themselves. If you’re watching from the side, remember that the ball’s contact with the court—not where it bounces afterward—is what matters.
What to Check at a Local Grass Court
If you’re booking a grass court, take a moment to look over the markings before you start. Clear lines make singles and doubles boundaries easier to follow, and they can reveal whether a court is ready for a match.
- Check that the singles and doubles sidelines are both visible.
- Look for a clear center mark and center service line.
- Notice any worn or muddy areas near the baseline and service boxes.
- Ask the venue whether recent rain or maintenance has affected play.
- Agree with your opponent on how you’ll handle uncertain calls.
Grass courts can change in feel as the turf wears through a session or across a playing season. The lines stay in the same places, but the surrounding surface may not look equally crisp everywhere. A quick check helps you avoid confusion once the match gets tight.
Frequently Asked Questions
Is a ball on the line in on a grass court?
Yes. If the ball touches any part of a line that marks the area in play, it is in. For example, a singles ball touching the singles sideline is good.
Are grass court lines different from hard-court lines?
No. The court layout and standard dimensions are the same. The main difference is how the markings are applied and how clearly they show against the playing surface.
Why can grass court lines look worn?
Foot traffic, mowing and weather can affect the turf and its markings. Baselines often see heavy use, so the grass around them may wear faster than less-traveled areas.
What is the alley used for?
The alley is the strip between the singles and doubles sidelines. It is out in singles and in during doubles.
Final Thoughts
Grass court lines use the familiar tennis layout: baselines, singles and doubles sidelines, service lines, a center service line and center marks. The dimensions and basic calls are the same as on other surfaces, but turf wear and the low bounce can make close points feel different. Learn which lines apply to your match, check the court before you play and give yourself a clear view of the ball’s landing spot.
