OEE Calculator

How to Calculate OEE

OEE (Overall Equipment Effectiveness) is the gold-standard metric for how well a manufacturing operation runs. It combines three factors into a single percentage: OEE = Availability × Performance × Quality. This calculator applies the standard formula used across discrete manufacturing.

The Three OEE Factors

• Availability = Run Time / Planned Production Time. It captures losses from breakdowns and changeovers.
• Performance = (Ideal Cycle Time × Total Count) / Run Time. It captures slow cycles and minor stops.
• Quality = Good Count / Total Count. It captures defects and rework.

What Is a Good OEE Score?

There is no universal good score for every process. 85% is a widely cited reference, but product mix, planned-time rules, ideal-cycle definition, constraints and data quality change what the number means. Preserve the calculation contract, trend the same scope over time and investigate the factor losses behind it. The Six Big Losses guide helps turn a score into an improvement question.

Define the OEE data contract

Record what counts as planned production time, which stops are downtime, who owns the ideal cycle time, how changeovers and rework are treated, and where total/reject counts originate. An OEE percentage without these definitions is not comparable across shifts, lines or sites. Export the result above or start with the blank shift CSV to preserve the inputs.

Calculate OEE Automatically From the PLC

The most reliable OEE comes straight from the control system, not a clipboard. Availability comes from machine-state bits, Performance from a cycle or counter tag, and Quality from a reject counter. Our guide on how to calculate OEE shows the exact PLC tag mapping, and where MES fits for plant-wide rollups.