Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
OEE
69.3%
Availability
87.5%
Performance
83.3%
Quality
95.0%
Actual run time
420
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How to use this
- 1Enter planned production time (min).
- 2Enter downtime (changeover, breakdown, etc.) (min).
- 3Enter ideal cycle time per part (sec).
- 4Enter total parts produced.
- 5Enter good parts (no rework/scrap).
- 6Read your oee on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
OEE is the standard metric for how much of a machine's theoretical output actually becomes good parts. World-class is usually cited as 85%, typical discrete manufacturing runs 40-60%. The calculation multiplies three losses together: availability loss from downtime, performance loss from running slower than ideal cycle time, and quality loss from scrap and rework. Because the three factors multiply rather than add, a plant that looks fine on each individual number (90% availability, 90% performance, 90% quality) still only nets 73% OEE — that compounding is the whole point of tracking it this way instead of one blended number. Feed this from your MES or a shift log: planned production time, actual downtime minutes, ideal cycle time per part, total parts made, and good parts. Use it per machine, per shift, or per line, and track the trend weekly rather than chasing a single day's number, since changeover-heavy days will always score lower than long steady runs.
Worked example
Using the values the calculator loads with:
Inputs
- Planned production time: 480 min
- Downtime (changeover, breakdown, etc.): 60 min
- Ideal cycle time per part: 30 sec
- Total parts produced: 700
- Good parts (no rework/scrap): 665
Results
- OEE: 69.3%
- Availability: 87.5%
- Performance: 83.3%
- Quality: 95.0%
- Actual run time: 420
What each field means
Inputs
- Planned production time (min)
- The planned production time used in the calculation, measured in min. Starts at 480 min so you have a working example on load.
- Downtime (changeover, breakdown, etc.) (min)
- The downtime (changeover, breakdown, etc.) used in the calculation, measured in min. Starts at 60 min so you have a working example on load.
- Ideal cycle time per part (sec)
- The ideal cycle time per part used in the calculation, measured in sec. Starts at 30 sec so you have a working example on load.
- Total parts produced
- The total parts produced used in the calculation. Starts at 700 so you have a working example on load.
- Good parts (no rework/scrap)
- The good parts (no rework/scrap) used in the calculation. Starts at 665 so you have a working example on load.
Results
- OEE
- Returned as a percentage and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Availability
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Performance
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Quality
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Actual run time
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What counts as a 'good' OEE score?
85% is the textbook world-class benchmark, but that figure comes from discrete assembly with mature TPM programs. Most job shops and CNC operations run 45-65% and that's normal. Track your own trend rather than chasing 85% blindly — a 10-point improvement from 50% to 60% is worth more than obsessing over the last 5 points near the top.
Why does performance sometimes exceed 100%?
If your ideal cycle time is outdated or conservative, actual output can beat it, pushing performance over 100%. This calculator caps it at 150% to avoid absurd OEE numbers, but the real fix is updating the ideal cycle time to reflect current tooling and speeds.
Should changeover time count as downtime?
Yes, unless you're tracking a separate changeover-specific metric. Changeover is real time the machine isn't cutting good parts, and hiding it inflates availability artificially. Some plants track OEE with and without planned changeovers to separate the two loss types.
How is OEE different from utilization?
Utilization only measures whether the machine was scheduled to run versus idle. OEE goes further and asks whether the scheduled time was used at full speed making good parts. A machine can have 95% utilization and 55% OEE if it's running slow and scrapping parts.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
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Cycle Time vs. Demand Calculator
Find out if your process can keep up with orders, and how many stations you need.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). OEE Calculator (Overall Equipment Effectiveness). Retrieved from https://www.revenuelab.fyi/toolbox/oee-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/oee-calculator" target="_blank" rel="noopener">OEE Calculator (Overall Equipment Effectiveness) — RevenueLab</a> (2026).</p>
Source: [OEE Calculator (Overall Equipment Effectiveness) — RevenueLab](https://www.revenuelab.fyi/toolbox/oee-calculator) (2026).