Quality & Metrology worked example

Bilateral Tolerance with total bilateral tolerance band of 0.5 mm: a worked example

Push total bilateral tolerance band up to 0.5 mm and the picture changes. This example computes every intermediate figure at that operating point. Use it when a feature carries a symmetric plus or minus tolerance and you want to know how much usable margin is left after known sources of variation.

The inputs for this scenario

  • Total bilateral tolerance band: 0.5 mm (raised for this scenario; the documented default is 0.2)
  • Tolerance consumed by process variation: 0.08 mm (unchanged)
  • Tolerance consumed by measurement error: 0.03 mm (unchanged)
  • Tolerance consumed by fit or alignment: 0.02 mm (unchanged)

Working through the calculation

  • Applying the documented formula (Tolerance consumed = process variation + measurement error + fit or alignment) to the inputs above produces each figure below.
  • At this operating point the engine returns 0.37 units for remaining tolerance margin, the number this scenario is built around.
  • At this operating point the engine returns 0.13 value for tolerance consumed.
  • At this operating point the engine returns 0.5 value for total bilateral tolerance band.
  • At this operating point the engine returns 74 % for utilization.

How this compares with the baseline

  • Against the tool's baseline example, where total bilateral tolerance band sits at 0.2 mm and the headline result is 0.07 units, this scenario comes in 429% above the baseline at 0.37 units.
  • It sums the tolerance allocated to process variation, measurement error, and fit or alignment, then subtracts that from the total bilateral tolerance band to report the remaining margin and utilization. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Remaining tolerance margin: 0.37 units (headline result)
  • Tolerance consumed: 0.13 value
  • Total bilateral tolerance band: 0.5 value
  • Utilization: 74 %

Run it with your numbers

  • Every input above is editable in the live Bilateral Tolerance calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.