OEE Calculator
Enter planned time, downtime, ideal speed and shift output: instantly see Availability, Performance, Quality, OEE and how many minutes each loss cost you.
Fix the highlighted fields to see the result.
The 3 losses, in minutes
- Time that became good product–
- Availability loss–
- Speed loss–
- Quality loss–
What is 1 point of OEE worth?
With the ideal speed and planned time above, each percentage point of OEE equals this extra output — with the same line and the same crew.
How to calculate OEE
OEE (Overall Equipment Effectiveness) measures how much of the planned production time actually turned into good product at the ideal speed. It is the product of three factors:
Example with the calculator’s default values: a 480 min shift, 60 min of downtime, ideal cycle of 0.5 min per unit (2 units/min), 700 units produced and 20 rejected.
Availability
(480 − 60) ÷ 480 = 87.5%420 min running out of 480 planned. Loss: 60 min of downtime.
Performance
(0.5 × 700) ÷ 420 = 83.3%700 units are “worth” 350 min at ideal speed. Loss: 70 min of slow running and minor stops.
Quality
(700 − 20) ÷ 700 = 97.1%680 good units. Loss: 20 × 0.5 = 10 min spent making rejects.
OEE
87.5% × 83.3% × 97.1% = 70.8%Direct check: 680 × 0.5 ÷ 480 = 70.8%. In other words, 340 of the 480 min became good product.
Prefer an OEE calculator in Excel? In row 2 enter: planned time in min (A2), downtime in min (B2), ideal cycle in min/unit (C2), total units (D2) and rejects (E2). Then use:
- Availability:
=(A2-B2)/A2 - Performance:
=C2*D2/(A2-B2) - Quality:
=(D2-E2)/D2 - OEE:
=(D2-E2)*C2/A2
Or use the Copy result (Excel) button above and paste straight into your spreadsheet.
Questions about calculating OEE
What is the OEE formula?
OEE = Availability × Performance × Quality. Availability is run time divided by planned time; Performance is ideal cycle time times total units, divided by run time; Quality is good units divided by total units. Directly: OEE = good units × ideal cycle time ÷ planned time.
What is a good OEE?
The most quoted reference is 85% as “world class”, popularized by TPM. Below 60% usually means there is a lot of room for improvement, and 60% to 85% is a common range. These are market references, not rules: what matters most is measuring with the same rule every time and tracking your line’s progress.
How do I define the ideal cycle time?
Use the maximum speed the equipment has proven it can sustain for that product (demonstrated or nameplate capacity), not the day-to-day “realistic” target. If the ideal cycle is adjusted to what the line already does, the speed loss disappears from the metric — but it stays in your costs.
Why is my performance above 100%?
Performance above 100% means the line produced more than would be possible at the ideal speed you entered. Almost always the ideal cycle time is too slow (or the ideal rate too low) for that product. It is also worth checking that downtime was not overstated or that the total units do not include another shift.
Can I calculate OEE in Excel?
Yes. With planned time in A2, downtime in B2, ideal cycle in minutes per unit in C2, total units in D2 and rejects in E2, OEE is =(D2-E2)*C2/A2. A spreadsheet works for one line; with many lines and shifts it tends to miss minor stops and depends on re-typing — that is where an MES collects and calculates everything automatically.
In ProMOS™ MES this calculation is automatic
Shift by shift, with your company’s rules: downtime and output collected from the line, ideal cycle per product and machine, OEE and loss Pareto in real time — no spreadsheets.
