The Lines of a Tennis Court
Baseline: Doubles 36 feet / Singles 27 feet
The baseline runs parallel to the net and defines the farthest boundary, or back of the court, on each side. It’s where you will hit most of your groundstrokes (forehands and backhands) and the approximate location you’ll return serves. Any shots that land beyond this line are out of bounds.
Center Mark: 4 inches long
The center mark divides the baseline in half and runs perpendicular to the net. It defines the point you cannot cross when hitting a serve in either the deuce and ad court. It’s a great point of reference, as you’ll find coaches telling you to always return to the center of the baseline after you hit a groundstroke.
Service Line: 27 feet wide
The service line runs parallel to the net and marks the halfway point between the net and the baseline. It also marks the end of the service boxes. However, unlike the baseline, it extends only to the singles sidelines. Any serve that lands beyond this line in the court is out.
Center Service Line: 42 feet long (21 feet on each side of the court)
The center service line runs perpendicular to the net and meets the service line to create two equal-sized service boxes.
Singles Sidelines: 39 feet long
The singles sidelines also run perpendicular to the net and define the side boundaries of the court for singles matches.
Doubles Sidelines: 39 feet long
A few feet outside of the singles sidelines are the doubles sidelines. These sidelines run perpendicular to the net and define the side boundaries of the court for doubles matches.