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    Production / OEE

    OEE calculator

    Overall equipment effectiveness multiplies three ratios: how much of the planned time the machine ran, how fast it ran against its ideal cycle, and how much of what it made was good. Because it is multiplicative, three 90% factors produce 73%, not 90%.

    Planned480 minDowntime48 minThroughput53/h
    OEE
    79.2%
    Typical
    Availability
    90.0%
    432 of 480 planned minutes
    Performance
    92.6%
    Ideal cycle 60 s
    Quality
    95.0%
    380 good of 400
    Loss decomposition
    OEE is the product of three ratios; each one hides a different loss.
    79.2%
    Loss decomposition
    FactorValueLoss
    Availability90.0%10.0%
    Performance92.6%7.4%
    Quality95.0%5.0%
    OEE79.2%20.8%

    Availability losses are downtime; performance losses are speed and minor stops; quality losses are scrap and rework.

    Inspect the model
    Choose a quick result view, a scaled comparison, or the complete diagnostic set.
    OEE against downtime
    Downtime hits all three factors, not just availability.
    OEE against downtime0.00017.7335.4753.2070.9388.670m0m19m19m38m38m58m58m77m77m96m96m115m115m134m134m154m154m173m173m192m192mOEE %
    The three factors
    World-class targets are roughly 90% availability, 95% performance, 99% quality.
    The three factors0.00022.4244.8467.2689.68112.1090.00AvailabilityAvailability92.59PerformancePerformance95.00QualityQuality79.17OEEOEE%
    Canonical equations
    The exact relationships implemented by this engine.

    run time / planned time · Planned time excludes breaks and planned maintenance.

    (ideal cycle × count) / run time · Capped at 100%.

    good count / total count · Scrap and rework both count as loss.

    A × P × Q · Multiplicative: a 90/90/90 line runs at 73%.

    engineering methodology

    A clear path from inputs to results.

    Overall equipment effectiveness multiplies three ratios: how much of the planned time the machine ran, how fast it ran against its ideal cycle, and how much of what it made was good. Because it is multiplicative, three 90% factors produce 73%, not 90%.

    Step-by-step methodWorked exampleAssumptions explained

    How to use

    1. Enter planned production time excluding breaks.
    2. Enter downtime.
    3. Set the ideal cycle time and the counts.
    4. Read OEE and the three factors behind it.

    The formula

    OEE=A×P×QOEE = A \times P \times Q

    Reference: Total productive maintenance (Nakajima) definition of OEE.

    Worked example

    480 planned minutes, 48 downtime, 400 units, 380 good

    Inputs
    • Planned 480 min, downtime 48 min.
    • Ideal cycle 60 s/unit.
    • 400 units produced, 380 good.
    Calculation path
    1. 1

      Run time: 432 min; availability 90.0%.

    2. 2

      Ideal time for 400 units: 400 min; performance 400/432 = 92.6%.

    3. 3

      Quality: 380/400 = 95.0%.

    4. 4

      OEE: 0.90 × 0.926 × 0.95 = 79.2%.

    Result

    OEE 79.2% (A 90.0 · P 92.6 · Q 95.0).

    Interpreting the result

    The multiplicative structure is the point. A line that looks strong on every individual measure — 90% available, 93% fast, 95% good — is running at 79% of its potential. Improving the weakest factor moves OEE most, which is why the loss decomposition matters more than the headline number.

    Assumptions & limitations

    • Planned time excludes breaks and planned maintenance.
    • Performance is capped at 100%; a faster-than-ideal run does not create credit.
    • Single machine or line; no buffer or upstream starvation effects.

    Frequently asked questions

    What is a good OEE?

    85% is often quoted as world class. 60% is typical for discrete manufacturing; 40% is common in low-volume plants.

    Does OEE measure profitability?

    No. It measures equipment effectiveness, not whether the output is wanted or sold.

    Should planned maintenance count as downtime?

    No. It belongs in planned time, or availability is understated.

    Methodology last reviewed 2026-10-21. Results are informational and not financial or engineering advice — see our disclaimer.