Tolerance Stack-Up Calculator

Enter individual feature tolerances (bilateral, in mm). Compare worst-case and RSS (root-sum-square) stack-ups against a system tolerance.

System tolerance (mm):

Results

Worst-case stack-up: $T_{sys} = \sum T_i$—

RSS stack-up: $T_{sys} = \sqrt{\sum T_i^2}$—

System tolerance (target)—

Worst-case vs. system—

RSS vs. system—

RSS savings vs. worst-case—

Worst-case assumes all errors align in the same direction (conservative). RSS assumes independent, normally distributed errors (3σ). RSS is valid when n ≥ 4 and errors are truly independent.