Tolerance Stack Calculator
Calculate the nominal, minimum and maximum of a one-dimensional dimension chain. Use the worst-case limits to check whether an assembly gap can close or become an interference.
Enter your dimension chain
Use millimetres throughout. Select Add for dimensions that increase the gap and Subtract for dimensions that reduce it. Enter signed deviations, such as −0.10 and +0.10. Enter zero for a deviation that does not apply.
Check an assembly gap
A 25.00 mm opening with ±0.10 mm tolerance minus a 24.80 mm insert with −0.15/+0.05 mm deviations gives a nominal gap of 0.20 mm, a minimum of 0.05 mm and a maximum of 0.45 mm. The minimum uses the smallest opening and largest insert. The maximum uses the largest opening and smallest insert.
The model assumes the listed dimensions can reach their individual limits simultaneously. It covers linear dimensions along one axis. Evaluate geometric controls, temperature and deformation separately. See CNC machining tolerances explained for drawing guidance.