Identify what changed
A motor step angle, configured microstep value, pulley tooth count, belt pitch, screw lead, or reduction ratio can change the theoretical motion setting. Recalculate from those parts before touching a correction factor.
Separate pitch from lead
For a multi-start lead screw, pitch is the spacing between adjacent threads; lead is the travel per revolution. Multiply pitch by thread starts. A T8×8 screw commonly has 2 mm pitch and four starts, so its lead is 8 mm.
Use the firmware value that matches the machine
Marlin M92 expresses pulses as steps per unit. Klipper rotation_distance expresses travel per full motor revolution. They are inverse descriptions once full steps and configured microsteps are known.
Measure direct axis travel
Command a long, safe movement, approach the measurement from the same direction, and measure the carriage or gantry directly. Repeat the test. Do not use a printed cube because shrinkage, extrusion, skew, and first-layer effects contaminate the measurement.
Check pulse rate before raising speed
A correct distance setting can still demand too many pulses or too much motor RPM at high speed. Check pulse frequency, then validate torque, resonance, current, acceleration, and missed-step behavior on the machine.