OEE Calculator & Shift OEE Tracker
€17.99 · Excel template, digital download
- Production downtime events
- Planned vs unplanned downtime
- OPEN and CLOSED downtime events
- Production line and shift performance
Free calculator
Free OEE Calculator
Combine availability, performance and quality into one efficiency figure.
Overall Equipment Effectiveness
Needs validationEnter all five values to see your result.
Data check required
Availability
—
Operating Time ÷ Planned
Performance
—
Net Run Time ÷ Operating Time
Quality
—
Good Units ÷ Total Units
Where the Planned Production Time went
Each loss is taken from the time left after the previous one, so nothing is counted twice and the parts add up to the Planned Production Time.
| Component | Minutes | Share |
|---|---|---|
| Availability lossStop Time | ||
| Performance lossOperating Time − Net Run Time | ||
| Quality lossNet Run Time − Fully Productive Time | ||
| Fully Productive TimeGood units at the ideal speed | ||
| Planned Production Time | 100% |
- Operating Time
- —
- Planned − Stop Time
- Net Run Time
- —
- Ideal Cycle Time × Total Units
- Good Units (first pass)
- —
- Total − Defective
- Fully Productive Time
- —
- Ideal Cycle Time × Good Units
Planning an order? Check it against a target
OEE measures how well past production performed. Capacity planning looks forward: can a target quantity be made in the time available, how big is the potential shortfall, and how much additional planned production time would it need?
Open the Capacity Calculator with these valuesYour OEE is historical performance, not a guaranteed future result. Planned production time and your target are not passed, and you can edit everything.
What is OEE?
Overall Equipment Effectiveness (OEE) shows how much of your planned production time was truly productive. It combines three things into one percentage: how much of the time the line was running, how fast it ran, and how many units were good the first time. An OEE of 100% would mean good units only, at the ideal speed, with no stops.
Availability
The share of Planned Production Time during which the line was actually running. Stops such as breakdowns, changeovers and setup reduce it. Availability = Operating Time ÷ Planned Production Time.
Performance
How fast the line ran while it was running, compared with its ideal speed. Slow cycles and small slowdowns reduce it. Performance = Net Run Time ÷ Operating Time, where Net Run Time = Ideal Cycle Time × Total Units.
Quality
The share of units that were good the first time. Scrap, rejects and units that needed rework reduce it. Quality = Good Units ÷ Total Units, counting only first-pass good units.
OEE = Availability × Performance × Quality, which is the same as Fully Productive Time ÷ Planned Production Time.
The terms used here
- Planned Production Time
- The time you scheduled the line to produce, excluding scheduled breaks.
- Stop Time
- All stops inside Planned Production Time: breakdowns, changeovers, setup, material shortages and other stops.
- Operating Time
- Planned Production Time − Stop Time.
- Net Run Time
- Ideal Cycle Time × Total Units: the time the units made would have taken at the ideal speed.
- Fully Productive Time
- Ideal Cycle Time × Good Units: the time spent making good units at the ideal speed.
Limits of this calculator: it covers one product or process with a single Ideal Cycle Time, and Quality counts only units that were good the first time. It gives a snapshot for one shift, run or period. It does not keep history or compare shifts and lines.
Worked example
An illustrative shift on a packaging line: 480 minutes scheduled, 47 minutes of stops, a 30-second ideal cycle, 780 units produced and 15 of them defective. These are the values the calculator opens with.
| Measure | Value | How |
|---|---|---|
| Planned Production Time | 480 min | An 8-hour shift scheduled to run, breaks excluded |
| Stop Time | 47 min | Changeovers, a breakdown and short stops |
| Operating Time | 433 min | 480 − 47 |
| Net Run Time | 390 min | 30 s × 780 units ÷ 60 |
| Good Units | 765 | 780 − 15 defective |
| Fully Productive Time | 382.5 min | 30 s × 765 units ÷ 60 |
| Availability | 90.2% | 433 ÷ 480 |
| Performance | 90.1% | 390 ÷ 433 |
| Quality | 98.1% | 765 ÷ 780 |
| OEE | 79.7% | 382.5 ÷ 480 (= 0.902 × 0.901 × 0.981) |
Where the 480 minutes went: 47.0 min availability loss + 43.0 min performance loss + 7.5 min quality loss + 382.5 min fully productive = 480.0 min. The biggest single loss here is Stop Time, followed by slow running.
OEE calculator FAQ
What is a good OEE score?
There is no single answer. OEE is often discussed against reference points such as 85% for discrete manufacturing, but what is achievable depends on the product, the process and how the inputs are defined. The most useful comparison is your own line over time, and the size of each loss.
Should scheduled breaks be included in Planned Production Time?
No. Leave out scheduled breaks, such as lunch and tea breaks, when you enter Planned Production Time. Then do not count them again as Stop Time.
What goes into Stop Time?
Every stop that happens during Planned Production Time: breakdowns, changeovers, setup and adjustments, waiting for material or operators, and other stops. How you treat very short stops depends on your own rules. If you record them as stops, they lower Availability. If you do not, they show up as lost speed in Performance.
Why is my Performance above 100%?
Performance above 100% means the units produced would have needed more time than the line was running, at the ideal cycle time. That points to a data problem: an Ideal Cycle Time that is too slow, a Total Units figure that is too high, or Stop Time or Planned Production Time that are not consistent with each other. The calculator does not cap the value. It shows the maths and warns you to check the inputs.
How should I count rework?
Quality uses units that were good the first time. Units that were scrapped, rejected or reworked are not counted as good first-pass units, so enter them as Defective Units.
What is the Ideal Cycle Time?
The fastest time per unit that the process can sustain, in seconds per unit. Use the rated or demonstrated best speed rather than the average actual speed. If it is set to the average, Performance will look better than it is.
Can I use this for several products?
Not in this version. It uses one Ideal Cycle Time for one product or process. For a mix of products, calculate each product or run separately.
Is my data stored or sent anywhere?
No. The calculation runs in your browser and nothing you type is sent to our servers.
Go further than a single calculation
This free calculator works on one set of numbers at a time and never needs a purchase. If you want to record OEE and downtime over time, SmartFactoryTools has Excel workbooks for that, sold through Etsy:
OEE Dashboard & Downtime Cost Tracker
€28.99 · Excel template, digital download
- Track planned and unplanned downtime by date, shift, production line, SKU and reason
- Calculate Availability, Performance, Quality and OEE automatically
- Monitor production output, scrap / rejects and labor productivity
- Estimate lost production capacity caused by downtime