Suggestions on how to mark out a court
The following procedure is for the usual combined doubles and singles court. (See note at foot for a court for one purpose only.)
First select the position of the net; a straight line 42 feet (12.80 m) long. Mark the centre (X on the diagram) and, measuring from there in each direction, mark:
Insert pegs at A and B and attach to them the respective ends of two measuring tapes. On one, which will measure the diagonal of the half-court, take a length 53’1″ (16.18 m) and on the other (to measure the sideline) a length of 39’0″ (11.89 m). Pull both taut so that at these distances they meet at a point C, which is one corner of the court. Reverse the measurements to find the other corner D. As a check on this operation it is advisable at this stage to verify the length of the line CD which, being the baseline, should be found to be 36’0″ (10.97 m); and at the same time its centre J can be marked, and also the ends of the inner sidelines (c, d), 4’6″ (1.37 m) from C and D.
The centreline and serviceline are now marked by means of the points F, H, G, which are measured 21’0″ (6.40 m) from the net down the lines bc, XJ, ad, respectively.
Identical procedure the other side of the net completes the court.
If a singles court only is required, no lines are necessary outside the points a, b, c, d, but the court can be measured out as above. Alternatively, the corners of the baseline (c, d) can be found if preferred by pegging the two tapes at a and b instead of at A and B, and by then using lengths of 47’5″ (14.46 m) and 39’0″ (11.89 m). The net posts will be at n, n, and a 33’0″ (10 m) singles net should be used.
When a combined doubles and singles court with a doubles net is used for singles, the net must be supported at the points n, n, to a height of 3 feet 6 inches (1.07 m) by means of two singles sticks, which shall be not more than 3 inches (7.5 cm) square or 3 inches (7.5 cm) in diameter. The centres of the singles sticks shall be 3 feet (.914 m) outside the singles court on each side.
To assist in the placing of these singles sticks it is desirable that the points n, n, should each be shown with a white dot when the court is marked.
As a guide for international competitions, the recommended minimum distance between the baselines and the backstops should be 21 feet (6.40 m) and between the sidelines and the sidestops the recommended minimum distance should be 12 feet (3.66 m).
As a guide for recreational and Club play, the recommended minimum distance between the baselines and the backstops should be 18 feet (5.48 m) and between the sidelines and the sidestops the recommended minimum distance should be 10 feet (3.05 m).
As a guide, the recommended minimum height to the ceiling should be 30 feet (9.14 m).
Extract from ITF Rules of Tennis 2011