Sit-and-Reach Flexibility Calculator

About this calculator

The sit-and-reach test measures hamstring and lower-back flexibility by having you sit with legs extended and reach forward along a measured box or ruler as far as possible, and the resulting distance is compared against normative percentile tables built from large population samples, typically broken down by age and sex since flexibility naturally varies across both.

Physical education teachers, personal trainers and fitness assessors use this test as part of standard fitness batteries (such as the FitnessGram or YMCA protocols) because it requires almost no equipment and gives an easily repeatable measure of flexibility, and expressing a raw reach distance as a percentile makes it meaningful by showing where that result sits relative to other adults of the same age and sex rather than as an isolated number.

This calculator takes your sit-and-reach distance, age and sex, and returns your estimated flexibility percentile compared with adult population norms.