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Tolerance

Tolerance Stack-Up Calculator

Add a one-dimensional chain of signed dimensions and compare guaranteed worst-case accumulation with an RSS statistical estimate.

LOCAL CALC / TOLERANCE-STACK
NO DATA SENT

INPUT

Enter values

One line each. Use a negative nominal for a subtracting dimension; tolerances may be entered with either sign.

OUTPUT

READY

Enter known values and calculate.

Results stay on this device.
Shop-floor check

Do not use RSS as a guaranteed acceptance limit without a justified statistical model and process evidence. Safety-critical fits and compliance decisions require qualified review.

01 / METHOD

How to use this calculator

  1. Enter one signed dimension per line as nominal, plus tolerance, minus tolerance.
  2. Use a negative nominal when that dimension subtracts from the chain.
  3. Compare worst-case and RSS outputs in the context of the design requirement.

02 / APPLICATION

Where it helps

  • Checking one-dimensional assembly clearance
  • Comparing worst-case and statistical design margins
  • Reviewing asymmetric tolerances

03 / BOUNDARIES

Assumptions and limitations

Assumes

  • All dimensions lie on one scalar chain
  • Worst case permits every extreme simultaneously
  • RSS contributors are independent and suitably centered

Does not cover

  • RSS is not a guaranteed boundary
  • Geometric tolerance and datum effects are excluded
  • Correlated processes require a different model

04 / QUESTIONS

Frequently asked questions

How do I subtract a dimension?

Enter its nominal value as negative. Enter tolerance magnitudes normally; the calculator accumulates their possible effect on the chain.

Which result is guaranteed?

Worst case is the bounding arithmetic result if each source tolerance is itself guaranteed. RSS is only a statistical estimate.

Does this handle GD&T?

No. It is a one-dimensional scalar stack. Datum mobility, geometric zones, bonus tolerance, and vector loops need a dedicated analysis.