Quality & Metrology worked example

Unilateral Tolerance with one-sided tolerance allowance of 0.38 mm: a worked example

This scenario runs the unilateral tolerance calculation on the strong side: one-sided tolerance allowance of 0.38 mm, with every other input held at its documented default. Use it when a feature is limited in one direction only, such as a maximum runout or a minimum wall, and you need the usable margin.

The inputs for this scenario

  • One-sided tolerance allowance: 0.38 mm (raised for this scenario; the documented default is 0.15)
  • Allowance consumed by process variation: 0.06 mm (unchanged)
  • Allowance consumed by measurement error: 0.03 mm (unchanged)
  • Allowance consumed by setup or wear: 0.02 mm (unchanged)

Working through the calculation

  • Applying the documented formula (Allowance consumed = process variation + measurement error + setup or wear) to the inputs above produces each figure below.
  • At this operating point the engine returns 0.27 units for remaining tolerance margin, the number this scenario is built around.
  • At this operating point the engine returns 0.11 value for allowance consumed.
  • At this operating point the engine returns 0.38 value for one-sided tolerance allowance.
  • At this operating point the engine returns 71.05 % for utilization.

How this compares with the baseline

  • Against the tool's baseline example, where one-sided tolerance allowance sits at 0.15 mm and the headline result is 0.04 units, this scenario comes in 575% above the baseline at 0.27 units.
  • Use it on unilateral or single-limit features — GD&T geometric tolerances, plus-zero dimensions, minimum-material conditions — where deviation is permitted in one direction only. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Remaining tolerance margin: 0.27 units (headline result)
  • Allowance consumed: 0.11 value
  • One-sided tolerance allowance: 0.38 value
  • Utilization: 71.05 %

Run it with your numbers

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

Last reviewed 2026-05-12.