% defective output & cost. The Defect Rate Calculator takes units produced, defective units, cost per defect (rework, scrap, returns) and returns defect rate plus defects per million, cost of defects, first-pass yield. Results update as you type, and the formula is shown under the result so you can repeat it in your own spreadsheet.
Operational metrics turn time and capacity into money. Small improvements in utilisation, cycle time or defect rate compound across every unit produced, so measure them regularly. Use the worked example below to check the maths against your own figures.
How the Defect Rate Calculator works
A 1.5% defect rate is 15,000 defects per million; Six Sigma quality is 3.4. Multiply by the cost of a defect to see what quality problems cost.
Worked example
With the example values (units produced of 10000, defective units of 150, cost per defect (rework, scrap, returns) of $12), the defect rate is 1.50%; defects per million 15,000, cost of defects $1,800.00, first-pass yield 98.50%. Change any figure above and the result updates immediately; use Copy results to paste the summary into a note or email.
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Frequently Asked Questions
How is defect rate calculated?
defect rate = defects ÷ units produced; DPMO = defect rate × 1,000,000.
Which figures do I need?
Units produced, defective units, cost per defect (rework, scrap, returns). Take them from the same period and the same set of accounts or reports so the ratio is consistent, and check the example values as a guide to the units expected.
How do I use this in practice?
Measure the metric for a normal week, set a target, change one thing, and measure again. Operational gains come from many small, verified improvements.
