A standard-sized dressage arena is used for most sanctioned dressage shows and three-day events. To train your horse for the correct distances used in dressage tests, practicing in a standard arena is important. You can easily lay out a proper arena on any flat area with good footing that is at least 20 by 60 meters (66 by 197 feet).
Determine if your chosen area is large enough by measuring across the short side, and then down the proposed long side. The short side must be at least 66 feet (20 meters), and the long side must be at least 197 feet (60 meters).
Choose where your first corner stake should go, and drive in a marker with your hammer. Old pieces of rebar, pointed lathe stakes, or short pieces of 1-by-2 inch lumber will work well for this.
Measure across the short end, and set your second stake. Don't worry yet about being square with the other corner. We will square up the rectangle shortly.
Measure down the long side to the third corner. If your tape measure is too short to stretch the entire distance at once, use interim stakes to mark where you left off, and maintain the accuracy of your measurement.
Measure across the far short end to set the fourth stake. Now we will square up the corners.
Measure diagonally across the arena from Stake 1 to Stake 3, and jot down the measurement.
Measure diagonally across the arena from Stake 2 to Stake 4.
Move the corner stakes in or out so that each diagonal line is equal to 207.8 feet. We have rounded the exact measurements in converting meters to feet (20 meters = 65.6 feet and 60 meters = 196.8 feet). Likewise, we have rounded the diagonal line from 207.76 to 208 feet even.
After evening up the diagonal lines, re-measure your short and long sides to ensure they are correct.
Set the full set of dressage letters used in standard arenas as shown in the diagram, and in accordance with the measurements given below. D, L, X, I, and G are not physical letters; all the rest will be placed around the outside of the arena.
Begin by placing A and C halfway along the short sides. Measure from corner to corner and set a stake at the 33-foot mark (10 meters). This will be dead centre of your dressage letter. Since horses will enter the arena at A, set this letter back a few feet to allow horses to turn inside and start up the centre line.
Tie a long (at least 200 feet) string to Stake 2, and run it down to Stake 3. Stretch it tight, and tie it off. This is the edge of your arena. Set your letters just touching the string on the outside, so that they are lined up facing in. Do the same between Stake 1 and Stake 4 when setting letters on the other side of the arena.
Set E and B halfway down each long side as shown, at the 30-meter mark, or 98.4 feet.
Set H and M 6 meters (19.6 feet) from the end of the arena nearest C, and K and F, 6 meters from the end of the arena nearest A, as shown.
Set S, R, V and P 18 meters (59 feet) from the ends of the arena as shown.
Remove the stakes, string and any tools, and you're done laying out your standard dressage arena. It is not necessary to enclose a practice arena, but you may wish to mark your corners. Stakes, blocks or poles laid at right angles are all sufficient for the rider to spot the corner and avoid turning short.
For outdoor arenas, cut short stakes and paint the dressage letters on them. Drive them into the ground at the centre point where each letter should sit, and leave them in place so that you will not have to re-lay your arena each spring if you bring your dressage letters in for the winter.