What this calculator does
This site convention is max(0, 1 − |actual hours − planned hours| ÷ planned hours) × 100. It makes absolute estimate error visible on a 0–100% scale.
Inputs and formula
Use matching work-order and labor records for one stated reporting period; the formula and boundary are defined on this page.
When to use it
Use it to review the quality of completed job-plan estimates. It is not a universal industry formula, so retain this definition when reporting or comparing it.
Worked example and interpretation
8 planned hours and 9 actual hours gives 87.5%. Review the signed variance too: this measure intentionally gives the same score to an eight-hour over- or under-estimate.
Practical notes and limitations
Work orders with zero planned hours are excluded because the denominator is undefined. Segment unusual failures, scope changes, and interruption time; they should not be mistaken for a normal job-plan estimate.