Engineering Calculator
Tolerance Stack-Up Calculator
Evaluate assembly variation using worst-case limits, RSS stack-up, and Monte Carlo simulation. Enter dimensions manually, upload a CSV file, or load example data.
Use positive direction for dimensions that add to the stack and negative direction for dimensions that subtract from the stack. Tolerances may be symmetric or asymmetric.
Input Data
| Dimension | Nominal | + Tol | - Tol | Direction | Distribution | Action |
|---|
CSV columns accepted: Dimension, Nominal, PlusTol, MinusTol, Direction, Distribution. Direction can be +, -, add, subtract, 1, or -1.
Method Notes
Worst case adds the most unfavorable tolerance limits directly. It is conservative and useful for critical fit checks.
RSS combines independent tolerances using root-sum-square. It is less conservative than worst case and often closer to expected manufacturing behavior.
Monte Carlo simulates many assemblies using normal, uniform, or triangular assumptions for each component. Normal variation is modeled so the entered tolerance is approximately ±3σ.