OEE Calculator
Enter one run's numbers and get Availability, Performance, Quality, and Overall Equipment Effectiveness instantly — with every formula shown so you can see exactly where the losses are. Free, no sign-up.
Your shift numbers
Scheduled time the machine was expected to run (shift length minus planned stops like breaks).
Unplanned stops — breakdowns, setups, waiting on material. Run time is what's left.
The fastest realistic time to make one good part. The spec, not the average.
Every part the machine made this run — good and bad.
Parts that passed first time. Rework and scrap don't count.
Overall Equipment Effectiveness
77.8%
Typical
90.2%
Availability
Run ÷ Planned
88.3%
Performance
Ideal ÷ Actual
97.6%
Quality
Good ÷ Total
OEE = Availability × Performance × Quality
90.2% × 88.3% × 97.6% = 77.8%
Run time = 433 min (planned − downtime)
What OEE actually measures
Overall Equipment Effectiveness is a single number for how much good product a machine made versus how much it could have made if it ran perfectly. It's the product of three honest questions: was the machine available when it should have been, did it run at speed when it was on, and did it make good parts? A perfect 100% means no stops, no slow-downs, and zero scrap — which is why nobody hits it.
The value isn't the number, it's the breakdown. Two machines can both sit at 60% OEE — one bleeding it all to breakdowns, the other to scrap — and the fix for each is completely different. Splitting OEE into its three factors tells you which of the six big losses to attack first.
Calculating it by hand from a shift report — like this tool does — is the right way to start. The next step is to stop typing numbers in and let the machine report them itself: on a FANUC control you can read run state and part counts with FOCAS and Python and compute OEE live, without paying per machine for a monitoring product.
Frequently asked questions
How is OEE calculated?+
OEE is the product of three factors: Availability × Performance × Quality. Availability is run time divided by planned production time. Performance is the ideal cycle time multiplied by total parts, divided by run time. Quality is good parts divided by total parts. Multiply all three and you get Overall Equipment Effectiveness.
What is a good OEE score?+
85% is considered world-class for a discrete manufacturing process. Around 60% is fairly typical, and 40% is common for shops that have not started measuring yet — which means the improvement headroom is large. The number matters less than the trend: measure consistently and watch it move.
What are the six big losses OEE measures?+
OEE rolls up the six big losses into its three factors. Availability captures breakdowns and setup/adjustment losses. Performance captures idling/minor stops and reduced-speed losses. Quality captures start-up rejects and production rejects. Improving OEE means attacking whichever of these six is biggest.
Why is my Performance over 100%?+
A Performance factor above 100% almost always means the ideal cycle time is set too slow — the parts actually ran faster than the 'ideal' you entered. Ideal cycle time should be the fastest realistic time to make one good part (the theoretical best), not the average you observed.
Do I need a monitoring system to track OEE?+
No. You can calculate OEE by hand from a shift's numbers, which is exactly what this tool does. Automating it — pulling run time and part counts straight off the control — is the natural next step, and on a FANUC machine you can read those numbers yourself with FOCAS rather than paying per machine for a monitoring product.
Want this running automatically off your machines?
Live OEE from the control — no manual entry, no per-machine fee.