Operations · Manufacturing and packing lines
OEE calculator.
Enter one shift or one run: planned time, stop time, ideal cycle time, units made and units rejected.
A 480-minute shift with 60 minutes of stops, a 0.5-minute ideal cycle, 720 units made and 18 rejected has an OEE of 73.1%: availability 87.5%, performance 85.7%, quality 97.5%.
Your numbers
Your result
What OEE tells you
OEE answers one question: of the time you planned to make product, how much was spent making good product at full speed? The number is useful mostly because it splits the answer into three losses with different owners. Stops belong to maintenance and changeover planning, slow running belongs to the process and the operators, and rejects belong to quality. A single OEE figure of 73% does not say which one to fix; the three lines under it do, and this page prices each one in minutes.
The NIST report cited below points out that OEE has several definitions in use. This page uses the three-factor form it calls preferred, and treats every stop you enter as availability loss, so your figure will differ from a plant that excludes planned changeovers. Compare like with like.
Worked example
One shift has 480 minutes planned and 60 minutes of stops, so the line ran for 420 minutes: availability = 420 / 480 = 87.5%. The ideal cycle is 0.5 minutes per unit and 720 units came off, so 720 x 0.5 = 360 minutes of work at ideal speed: performance = 360 / 420 = 85.7%. Of the 720 units, 18 were rejected, so quality = 702 / 720 = 97.5%.
OEE = 0.875 x 0.857 x 0.975 = 73.1%. The same figure comes straight from the good units: 702 x 0.5 = 351 productive minutes out of 480 planned. The 129 minutes that did not count split into 60 lost to stops, 60 lost to slow running and 9 lost to rejects.
How it is calculated
- Run time = planned production time − stop time. Availability = run time / planned production time.
- Performance = (ideal cycle time x total units) / run time. Above 100% means the ideal cycle time or the count is wrong, so the page warns.
- Quality = (total units − rejected units) / total units.
- OEE = availability x performance x quality.
NIST Advanced Manufacturing Series 100-31 describes OEE as a measure of a manufacturing operation’s performance relative to its full potential, gives a simple version (fully productive time divided by planned production time) and a preferred version based on availability, performance and quality, and refers readers to ISO 22400 for commonly accepted calculations and timing rules. Calculation as of October 26, 2026; the formula does not carry a rate table, so there is nothing that goes stale.
What this does not cover
- Whether your plant treats changeovers, breaks or starved-line time as planned or unplanned. ISO 22400 sets timing rules; this page does not reproduce them.
- Any target. This page makes no claim about what a good OEE is for your industry, because no source was opened for one.
- Multiple products with different cycle times in one shift. Run each product separately, or use a weighted ideal time as the cycle input.
Sources
Common mix-ups
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Often assumedOEE has one universal definition, so any two OEE figures can be compared.
What the source saysNIST says there are currently multiple definitions, interpretations, and calculations for OEE, and points to ISO 22400 for commonly accepted calculations with specific timing rules. Compare figures only when the definitions match. [1]
Checked against these sources on .
Frequently asked questions
What is OEE?
Overall equipment effectiveness is availability x performance x quality. NIST describes it as a measure of how an operation performs relative to its full potential during a typical run.
What is the OEE formula?
OEE = availability x performance x quality. Availability is run time over planned time, performance is ideal time for the units made over run time, and quality is good units over total units.
What counts as an availability loss?
Anything that stops the line during planned production time. Plants differ on whether planned changeovers count, and NIST notes there are multiple OEE definitions, so state your rule when you compare figures.
Why is my performance over 100%?
The ideal cycle time is probably set too slow, or the unit count includes units from outside the run time. Fix the input before using the OEE.
What is a good OEE?
This page does not give one. A benchmark only means something against the same definition on the same kind of line, and no benchmark source was opened for this page.
Estimate only
This page is a planning aid, not safety, engineering or legal advice. Results use the numbers you enter and the formulas and sources named above, as read on October 26, 2026. Everything runs in your browser; nothing is sent anywhere.