Free OEE calculator: availability, performance and quality
Calculate overall equipment effectiveness (OEE) for a machine, line or shift in seconds. Enter the planned production time, the downtime, the ideal cycle time and the total and good counts, and get OEE with its three factors, a dashboard against your target and a breakdown of the lost minutes.
OEE is the standard measure of total productive maintenance (TPM) and lean manufacturing, used to find where production time is lost and to track improvement.
How the OEE Calculator works
Availability is the run time divided by the planned time, performance compares the ideal time for the parts produced with the run time, and quality is the share of good parts. OEE multiplies the three. The loss chart converts them into minutes of downtime, speed loss and quality loss.
The verdict names the biggest loss and suggests the next step, for example a Pareto chart of downtime reasons.
When to use it
Use OEE for daily shift reports, for comparing machines and lines, to prioritise improvement projects and to measure the effect of SMED changeovers, maintenance programmes and scrap reduction. Calculate it per shift or per day with the same definitions, so the trend is meaningful.
The three factors point to different tools: availability to maintenance and changeover work, performance to small stops and speed, quality to Pareto analysis and root cause work.
PDF report in one click
Generate an OEE report as a PDF with your header (line, shift, product), the dashboard, the factors, the loss chart and the calculation table, for the shift meeting or a TPM board.
Private: everything runs in your browser
The OEE calculator runs in your browser and does not store or send production data anywhere.
How OEE is calculated
- Availability = run time / planned production time.
- Performance = ideal cycle time × total count / run time.
- Quality = good count / total count.
- OEE = availability × performance × quality.
The loss chart translates the three factors into minutes: downtime, speed loss and the time spent on scrap and rework, which shows where an improvement pays off most.
Frequently asked questions
›What is a good OEE?
About 85 % is often quoted as world class for discrete manufacturing (90 % availability × 95 % performance × 99.9 % quality). Typical plants are between 40 and 60 %. Compare with your own history rather than with a universal number.
›What counts as downtime?
Unplanned stops (breakdowns) and planned stops inside the planned production time, such as changeovers and adjustments. Breaks and periods without orders are excluded from the planned time.
›Why is my performance above 100 %?
The ideal cycle time is set too slow. Use the fastest cycle time the machine can sustain, from the design or the best demonstrated rate.