Flexibility Progress Tracker

This calculator tracks a single measurable gain -- range of motion in degrees, taken with a goniometer or similar tool at a joint like the hamstring or shoulder -- from where you started to where you are now, and projects when a Target Range of Motion will be reached. Total Improvement is just Current Range of Motion minus Starting Range of Motion, so both inputs move it by exactly one degree per degree, in opposite directions -- raising today's measurement adds degrees directly to the gain, and raising the starting figure subtracts the same amount. At the calculator's own default values (85° current, 60° starting), Current Range of Motion happens to show a larger effect on a percentage-change basis simply because it starts from a bigger number, not because the formula gives it more weight -- the two inputs are structurally identical, just opposite in sign. Target Range of Motion has no bearing on Total Improvement at all; that figure only compares two range-of-motion measurements, and Target Range of Motion instead drives the downstream Progress to Goal percentage and Remaining to Goal figure.

Weeks of Practice and Sessions per Week work differently from each other: Weeks of Practice sets your historical weekly pace (Total Improvement divided by however many weeks it took), while Sessions per Week scales that pace up or down against this calculator's 3-sessions-a-week baseline for the forward-looking Improvement per Week figure -- practicing more often than that speeds up the projected pace and shortens Projected Weeks to Goal, practicing less often slows both. Projected Weeks to Goal then applies a further 25% slowdown on top of that pace, on the assumption that flexibility improvements taper as you approach a joint's structural limit. That taper factor is a general modeling assumption, not something measured from your own data, so treat Projected Weeks to Goal as a loose estimate rather than a guarantee, especially close to your target.