A sit and reach test is usually conducted with special equipment, but you can measure your results at home as well. Ordinarily, you would use a device called a sit and reach box, which has a vertical flat surface you place your feet against and a horizontal surface above that with a ruler to measure how far you can reach. Approximate your own version of this by using a stair and a ruler as your sit and reach box.
Find a step in your home with a flat landing at its base. The bottom step in a flight of stairs will work, as will a single step at your front door or elsewhere in your home. If you don't have any steps, set a sturdy box that is no more than 12 inches tall in front of you. The box should be stationary. Set a ruler on top of the step or box, oriented to measure the depth of the step or box. You will need someone to help you read your measurement.
Warm up with moderate physical activity for a few minutes to loosen your muscles. When you are ready to perform the test, sit on the floor with your bare feet flat against the horizontal portion of the step or box you are using. Your feet should be right next to each other and your legs should be completely straight.
With both hands, stretch toward your toes and past them onto the surface of the step or box if you can. With the ruler and a helper, measure how many inches past the edge of the step your fingertips can reach. If you cannot reach the edge, measure the distance between your fingertips and the step and count it as a negative number.
The President's Challenge physical fitness sit and reach test sets 9 inches as the edge of the step so all participants score positive numbers. If you are using your results for this test, add 9 inches to your score.