OEE (overall equipment effectiveness) tells you what share of a machine's planned time turned into good parts at full speed. It is availability × performance × quality, so a machine that ran 84% of the shift, at 86% of its ideal speed, with 96% good parts, has an OEE of about 69%. This calculator works out the three factors and the OEE from one shift's numbers, then puts a rupee figure on the gap between your OEE and 100%.
How the calculator works
The calculator takes seven inputs:
- Planned production time (min per shift). The time you intended to run: shift length minus planned breaks. OEE.com, the reference site run by Vorne, starts the calculation by removing "Shift Time where there is no intention of running production (typically Breaks)".
- Stops (min). All the time the machine was meant to run but did not: breakdowns, waiting for material, setups and changeovers, no operator.
- Ideal cycle time (seconds per part). The fastest cycle the process can achieve in good conditions, not the average you usually see.
- Parts made. Everything the machine produced in the shift, good and bad.
- Good parts. Parts that passed first time, without rework.
- Machine or line hour rate (₹/h). What an hour of this machine or line costs you. The machine hour rate calculator shows how to build one.
- Shifts a year. How many shifts like this one the machine runs.
The formulas, the standard ones published on OEE.com:
Run time = planned production time − stops
Availability = run time ÷ planned production time
Performance = (ideal cycle time × parts made) ÷ run time (capped at 100%)
Quality = good parts ÷ parts made
OEE = availability × performance × quality
Lost-time cost per year = planned minutes × (1 − OEE) ÷ 60 × hour rate × shifts a year
Performance is capped at 100%. OEE.com notes that performance "should never be greater than 100%"; if it comes out higher, your ideal cycle time is set too slow. If the calculator shows exactly 100% performance, check that input before trusting the result. Quality is capped at 100% in the same way, so if good parts come out higher than parts made, recheck your counts.
Worked example (India)
One CNC turning cell on an 8-hour shift with 480 planned minutes after breaks. All figures are assumptions for illustration; they are the calculator's default inputs.
| Input | Value | Basis |
|---|---|---|
| Planned production time | 480 min | assumption |
| Stops | 75 min | assumption: breakdown, material wait, one setup |
| Ideal cycle time | 40 s/part | assumption |
| Parts made | 520 | assumption |
| Good parts | 500 | assumption |
| Machine hour rate | ₹900/h | assumption |
| Shifts a year | 300 | assumption: one shift, 300 days |
| Run time | 405 min | 480 − 75 |
| Availability | 84.4% | 405 ÷ 480 |
| Performance | 85.6% | 40 × 520 = 20,800 s ÷ (405 × 60 = 24,300 s) |
| Quality | 96.2% | 500 ÷ 520 |
| OEE | 69.4% | 0.844 × 0.856 × 0.962 |
| Lost-time cost per year | ₹6.60 lakh | 480 × 30.6% = 146.7 min ÷ 60 × ₹900 × 300 |
A quick check: OEE also equals good parts × ideal cycle time ÷ planned time. Here that is 500 × 40 s = 20,000 s against 28,800 s planned, or 69.4%. The 146.7 lost minutes a shift split into three parts:
| Loss | Minutes per shift | ₹ per year at ₹900/h |
|---|---|---|
| Stops (availability) | 75.0 | ₹3.38 lakh |
| Running slow or micro-stops (performance) | 58.3 (405 − 520 × 40 s) | ₹2.63 lakh |
| Defective parts (quality) | 13.3 (20 × 40 s) | ₹0.60 lakh |
| Total | 146.7 | ₹6.60 lakh |
The split matters more than the headline. Nearly 60 minutes a shift go to slow running and short stops that rarely make it into a logbook, almost as much as the stops everyone remembers.
What typical numbers look like
- World class is 85%; most plants are near 60%. OEE.com treats 85% as world class and says most companies are "closer to 60%".
- Measured data agrees. Evocon's data from 3,500+ machines in 50+ countries (May 2023 to June 2024) puts most manufacturers at 55–60% OEE. Evocon estimates that roughly 6% of organisations reach 85% on yearly averages, and probably closer to 3% once calculation errors are removed.
- India by sector. A 2026 benchmark from a monitoring vendor gives typical OEE of 60–75% for auto Tier 1, 40–58% for Tier 2–3 suppliers, 50–68% for electronics assembly, 45–60% for food processing, 40–55% for textiles and garments and 50–65% for plastics and packaging (TeepTrak). The source sells monitoring, so read these as indicative, not audited.
- Hand-logged numbers run high. The same vendor reports that recorded downtime typically rises 30–50% when plants move from manual to automated tracking (TeepTrak), which means a hand-calculated OEE is usually too flattering.
- Component averages. We found no credible public source for typical availability, performance or quality figures in Indian plants. Measure your own.
What this number does not tell you
- Whether the lost minutes could have been sold. The ₹ figure values every lost minute at the full hour rate, as if each one could have become a sold part. That is right only for your bottleneck machine, or when you are sold out. On a non-constraint machine that waits for the bottleneck anyway, recovering 30 minutes adds no output, and most of the ₹ figure is cost you carry, not money you lose. Run the calculator on the constraint first.
- Whether the hour rate is all cash. Depreciation and rent are paid whether the machine runs or not; power and tooling are mostly not spent while it stands. The figure is cost not recovered, not cash spent.
- Whether your ideal cycle time is honest. A generous ideal cycle time inflates performance and hides slow running. Use the fastest cycle the machine has proven, not the routing standard.
- Why the machine stopped. OEE shows how much was lost, not whether it was waiting for material, a setter or a decision. OEE.com's six big losses give a starting list of causes.
- What a camera cannot see. A camera can show when a machine is running, standing or being set up, and roughly how fast it is cycling. It cannot tell a part that looks good from one that is out of tolerance, so quality still has to come from inspection records. Ideal cycle time is an engineering input no camera can supply.
- Comparisons across machines. Two machines with the same OEE can have very different problems. One may lose time to stops, the other to slow running. Compare the three factors, not the single number.
Related guides
- OEE Explained for Indian Factories (with a Rupee Example)
- OEE Benchmarks for Indian Factories: What 'Good' Actually Looks Like
- Sanitation-Adjusted OEE for Indian Food Lines
- Spindle Utilisation: What 25%, 45% and 70% Mean on an Indian Floor
- Downtime cost calculator (₹)
FAQ
How do you calculate OEE? Multiply availability (run time ÷ planned time), performance (ideal cycle time × parts made ÷ run time) and quality (good parts ÷ parts made). With 405 of 480 minutes run, 520 parts at a 40-second ideal cycle, and 500 good parts, OEE is 84.4% × 85.6% × 96.2% = 69.4%.
What is a good OEE for an Indian factory? 85% is the usual world-class figure, and most plants worldwide sit near 55–60%. A 2026 vendor benchmark puts Indian Tier 2–3 auto suppliers at 40–58% and Tier 1 at 60–75%. Your own trend matters more than any benchmark.
Should planned breaks and maintenance count as downtime in OEE? No. Planned breaks come out before you start, so they are not in planned production time. Breakdowns, setups and waiting all count as stops and reduce availability.
Why does my performance come out above 100%? Because the ideal cycle time you entered is slower than what the machine actually achieves. Performance cannot exceed 100%, so the calculator caps it. Reset the ideal cycle time to the fastest proven cycle.
How do I turn OEE into rupees? Multiply the lost share of planned time (1 − OEE) by planned hours, your hour rate and shifts a year. At 69.4% OEE, 480 minutes, ₹900 an hour and 300 shifts, that is about ₹6.60 lakh a year, but it is real money only on a bottleneck machine or when you can sell everything you make.
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