OEE Calculator
Calculate Overall Equipment Effectiveness from availability, performance, and quality.
Calculator
No signup required. Results are indicative—verify for your standards.
Availability: 87.5% · Performance: 83.3% · Quality: 94.3%
OEE: 68.8%
Formula
OEE = Availability × Performance × Quality. Availability = (Planned time − Downtime) / Planned time. Performance = (Ideal cycle time × Actual output) / Run time. Quality = Good units / Total units produced.
Example calculation
Planned 480 min, downtime 60 min, ideal cycle 1 min/unit, actual output 350 units, good units 330. Availability = 420/480 = 87.5%. Performance = (1×350)/420 = 83.3%. Quality = 330/350 = 94.3%. OEE = 0.875×0.833×0.943 = 68.8%.
Engineering notes
World-class OEE is considered 85%+. Most plants start at 40–60%. The six big losses: equipment failure, setup/adjustment, small stops, reduced speed, process defects, and startup rejects. Address the largest loss first for maximum improvement.
When to use this calculator
- TPM implementation — establish OEE baseline and track improvement as TPM activities progress
- Production capacity analysis — determine true available capacity from OEE before committing new orders
- Maintenance effectiveness — measure whether preventive maintenance investment is improving availability
- Shift comparison — identify which shift or operator achieves best OEE to share best practices
- Capital expenditure avoidance — prove existing capacity is sufficient after OEE improvement before approving new equipment
Frequently asked questions
- What is a good OEE score?
- OEE benchmarks: 85%+ is world-class. 60–85% is typical for manufacturers with active improvement programmes. Below 60% is common in plants without structured maintenance — there is substantial room for improvement. Individual components matter: world-class availability >90%, performance >95%, quality >99.9%. Most plants suffer most in performance (speed losses) and availability (breakdowns and changeovers).
- What are the six big losses in OEE?
- Availability losses: (1) Equipment failure/breakdown, (2) Setup and adjustment time. Performance losses: (3) Minor stoppages and idling, (4) Reduced speed (running below ideal rate). Quality losses: (5) Process defects and rework, (6) Startup/startup rejects during warm-up. TPM targets all six big losses with separate countermeasures: PM for breakdowns, SMED for setup time, autonomous maintenance for minor stoppages.
- Should I use planned production time or total calendar time for OEE?
- Use planned production time (scheduled shift time minus planned maintenance, meals, and breaks). This is the standard OEE definition and isolates equipment performance from scheduling decisions. If you also want to measure scheduling efficiency, calculate TEEP (Total Effective Equipment Performance) using total calendar time as the denominator. TEEP = OEE × Utilisation, and is always lower than OEE.