Cost of Poor Quality Calculator
Total the failure costs of work that was not right first time.
In short
Total the failure costs of work that was not right first time.
Formula: COPQ = Internal failure + External failure + Other identified failure costs
What this calculator does
Addition of the failure categories entered, with optional restatements per unit and as a share of revenue.
Use it to turn Currency, Internal failure costs (optional), External failure costs (optional), Other failure costs you have identified (optional), and the other shown inputs into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this professional & industry calculation.
Inputs and what they mean
- Currency
- — Amounts are shown in the currency you pick. No exchange rate is applied..
- Internal failure costs (optional)
- — Optional. Leave at 0 to exclude it from the result. Scrap, rework, re-testing, downgrading — found before delivery..
- External failure costs (optional)
- — Optional. Leave at 0 to exclude it from the result. Warranty, returns, recalls, complaint handling — found after delivery..
- Other failure costs you have identified (optional)
- — Optional. Leave at 0 to exclude it from the result. Only costs you have measured yourself. Nothing is added for unmeasured or hidden costs..
- Revenue for the same period (optional)
- — Optional. Leave at 0 to exclude it from the result. Used only to express the total as a share of revenue..
- Good units produced in the period (optional)
- — Optional. Leave at 0 to exclude it from the result. Used only to show the cost per good unit..
How to use it
- Enter your own figures — the calculator never fills in a rate, price or benchmark for you.
- Press Calculate to see the result.
- Read the formula, variables, assumptions and source below the result before you rely on it.
Formula
COPQ = Internal failure + External failure + Other identified failure costs.
Inputs used: Currency, Internal failure costs (optional), External failure costs (optional), Other failure costs you have identified (optional), Revenue for the same period (optional), Good units produced in the period (optional).
Edge handling: Internal failure costs (optional) is required.; Internal failure costs (optional) cannot be negative.; Internal failure costs (optional) must be no more than 1000000000000.; External failure costs (optional) is required.; External failure costs (optional) cannot be negative..
Worked example
Internal and external failure costs for one quarter
- Start with Currency: USD, Internal failure costs (optional): 115000, External failure costs (optional): 84000, Other failure costs you have identified (optional): 0, Revenue for the same period (optional): 6200000, Good units produced in the period (optional): 48000.
- Apply the method: COPQ = Internal failure + External failure + Other identified failure costs.
- Failure costs only — prevention and appraisal are excluded.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Inputs outside the supported range are rejected rather than forced into a result.
- The result depends on the values you enter for this cost of poor quality calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Reference: American Society for Quality — Cost of quality — prevention, appraisal and failure costs
Last reviewed:
Common questions
Where does this formula come from?
ASQ cost of quality: the cost of poor quality comprises internal and external failure costs, excluding prevention and appraisal. See the source link on this page.
What kind of calculation is this?
The failure half of the cost-of-quality model: costs that would disappear if nothing failed. Prevention and appraisal are excluded.
What are its limits?
Unmeasured failure costs — lost sales, reputation, management time — are not included, and no estimate is invented for them. The total covers the period whose costs were entered. A measured cost of poor quality, an industry benchmark and an organisation's target are three different things.
How do I use the Cost of Poor Quality Calculator?
Enter the required values for Currency, Internal failure costs (optional), External failure costs (optional), Other failure costs you have identified (optional), Revenue for the same period (optional), and the other fields shown. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Cost of Poor Quality Calculator use?
COPQ = Internal failure + External failure + Other identified failure costs The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone. Check the formula, example, and limitations on this page before using the result for a real professional & industry decision.
Can the Cost of Poor Quality Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Formula, source and verification
The failure half of the cost-of-quality model: costs that would disappear if nothing failed. Prevention and appraisal are excluded.
The question it answers: What are we spending on quality, and how much of it is spent on things going wrong?
The formula
COPQ = Internal failure + External failure + Other identified failure costs
- IF — Internal failure
- (currency). Failures found before delivery.
- EF — External failure
- (currency). Failures found after delivery.
- OF — Other identified failure costs
- (currency). Optional. Only failure costs the organisation has measured itself.
- Rev — Revenue
- (currency). Optional. Used only to express the total as a share of revenue.
- U — Good units
- (count). Optional. Used only to show the cost per good unit.
Units: Currency in; currency, percentage and cost per unit out, in the currency selected.
What kind of calculation this is
Deterministic formula. The same inputs always give the same answer. The maths is fixed and does not depend on judgement.
Method
Addition of the failure categories entered, with optional restatements per unit and as a share of revenue.
Assumptions built into the result
- Mathematical: Only failure costs are entered; prevention and appraisal belong to the wider cost of quality.
Figures this calculator will never guess for you
- No benchmark, target or 'world class' value is supplied or implied; the result describes only the figures entered.
- No hidden-cost multiplier or 'iceberg' factor is applied.
- No share of revenue is suggested as normal or acceptable.
- Amounts are shown in the currency selected; no exchange rate is applied.
Limitations
- Unmeasured failure costs — lost sales, reputation, management time — are not included, and no estimate is invented for them.
- The total covers the period whose costs were entered.
- A measured cost of poor quality, an industry benchmark and an organisation's target are three different things.
Source and version
- Standard or reference
- Cost of poor quality — ASQ (ASQ cost of quality: the cost of poor quality comprises internal and external failure costs, excluding prevention and appraisal.)
- Published source
- American Society for Quality — Quality resources
- Formula version
- Version 1
- Verification
- Reviewed against the cited source on
- How much weight the source carries
- Standards or government
- Applies to
- Currency
- Amounts stay in the currency you choose; no exchange rate is applied.
Cite this page
Free Calculator. (2026, September 16). Cost of Poor Quality Calculator. https://freecalculator.tech/tools/copq-calculator
"Cost of Poor Quality Calculator." Free Calculator, 16 Sept. 2026, https://freecalculator.tech/tools/copq-calculator.
Cost of Poor Quality Calculator — Free Calculator, https://freecalculator.tech/tools/copq-calculator
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