The Universal Tennis Court

The tennis court, which you can see below, makes a rectangle measuring 78 feet long and 27 feet wide for singles, 36 feet wide for doubles. The doubles alleys (on either side of the singles court) account for the extra width of the doubles court.

Figure 1

Getting caught in the net

The court is divided into two equal halves by the net, which is anchored to the netposts just outside the boundary lines that make up the court. The net is usually made of a soft, mesh material, and it customarily has an adjustment strap in the center. (Some public courts have steel nets; just try not to run into them!)

You use the adjustment strap to achieve regulation net height. The net must be 36 inches high at the center strap and 42 inches high at either side of the court. Unfortunately, nets with center straps at some public courts are about as rare as basketball rims with nets! Not to worry. You don't have to cut down your favorite stickball bat to substitute for the center strap. You don't really need a center strap. Just take a cloth tape measure and check the center height of the net. If it's below 36 inches, give the net some slack. Don't worry about the height at the sides. When the net is 36 inches high at the center, you'll be fine.

Laying down the lines

The baselines define the farthest end of the court on both sides of the net. The baselines (78 feet) are the same regardless of whether you're playing singles or doubles. (See Figure 1)

Right smack dab in the middle of the baseline, you can see a center line, which (as you may suspect) divides the court into two equal parts. The center line becomes important when you serve, which you can read more about in my other posts.

The lines at the longer sides of the rectangle are called the sidelines. The sidelines are the only boundary lines that differ for singles and doubles. The singles sidelines run parallel to and inside of the sidelines created by the doubles alleys.

Inside the court you find the service lines, which are perpendicular to the sidelines and parallel with the baselines and the net. The service lines are 21 feet from the net, and each service line is divided in half by the center line.

The service lines, the center lines, and the net create four distinct boxes on either side of the net, each service box measuring 21 feet long and 13 1/2 feet wide.

On each side of the net, the center line divides the service boxes into an ad side and a deuce side, which you can see in Figure 2. Your serve always needs to clear the net and land inside the appropriate service box when you keep score.

Figure 2