OEE Calculator

Combine three already-calculated factors into Overall Equipment Effectiveness (OEE). Enter availability, performance and quality as percentages. OEE (%) = (availability ÷ 100) × (performance ÷ 100) × (quality ÷ 100) × 100. The tool multiplies the fractions; it does not average the percentages.

Assumptions & limits

• Each factor must be a finite percentage from 0 to 100 inclusive; decimal percentages are accepted. Enter 90 for 90%, not 0.90. Empty fields are rejected rather than treated as a zero factor.
• Use factors for the same equipment, measurement period and counting basis. This page takes the factors as inputs; it does not calculate them from downtime, ideal cycle time, output counts or rejects.
• The result is between 0% and 100%. A performance input above 100% is rejected rather than capped. The tool does not assign a benchmark, grade or improvement target.

Availability 80%, performance 90% and quality 95%.

1. Convert percentages to fractions: 80 ÷ 100 = 0.8, 90 ÷ 100 = 0.9, and 95 ÷ 100 = 0.95.
2. Multiply: 0.8 × 0.9 = 0.72; 0.72 × 0.95 = 0.684.
3. Convert back to a percentage: 0.684 × 100 = 68.4%.

OEE = 68.4%. The arithmetic average of the three inputs is not this result.

Availability 0%, performance 90% and quality 95% give a valid 0% OEE: any zero factor makes the product zero. Performance 101% instead gives an error and no result. Exactly 100% is accepted for every factor.

The result is the combined fraction represented by all three factors. In the example, that fraction is 0.684. Multiplying fractions means OEE cannot exceed the smallest entered percentage. Use the individual factors to see what you supplied; OEE alone does not identify the cause of a loss or say whether performance meets your own target.

• OEE is availability × performance × quality. Percentage conversion, the synthetic example and the zero-factor behavior are arithmetic consequences of this formula. Manufacturing Extension Partnership (MEP)

Input ranges, the absence of raw production-data inputs and the absence of benchmark grading describe this implementation. Keep the measurement basis consistent when supplying factors; this tool does not check that basis.