Cost of Quality Calculator
Total prevention, appraisal, internal and external failure costs.
What this calculator does
Addition within the four named categories, with the conformance and non-conformance subtotals and each category's share of the total.
Inputs and what they mean
- Currency
- — Amounts are shown in the currency you pick. No exchange rate is applied..
- Prevention costs (optional)
- — Optional. Leave at 0 to exclude it from the result. Training, planning, process control, supplier development..
- Appraisal costs (optional)
- — Optional. Leave at 0 to exclude it from the result. Inspection, testing, audits, calibration..
- 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..
- 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..
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
CoQ = (Prevention + Appraisal) + (Internal failure + External failure)
Worked example
Four categories recorded for one quarter
Conformance and non-conformance are totalled separately.
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
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Reference: American Society for Quality — Cost of quality — prevention, appraisal and failure costs
Last reviewed:
Common questions
Formula, source and verification
The prevention-appraisal-failure model: conformance costs plus non-conformance costs, each category reported separately.
The question it answers: What are we spending on quality, and how much of it is spent on things going wrong?
The formula
CoQ = (Prevention + Appraisal) + (Internal failure + External failure)
- P — Prevention
- (currency). Training, planning, process control, supplier development.
- A — Appraisal
- (currency). Inspection, testing, audits, calibration.
- IF — Internal failure
- (currency). Failures found before delivery.
- EF — External failure
- (currency). Failures found after delivery.
- Rev — Revenue
- (currency). Optional. Used only to express the total as a share of revenue.
Units: Currency in; currency and percentages 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 within the four named categories, with the conformance and non-conformance subtotals and each category's share of the total.
Assumptions built into the result
- Mathematical: Each cost has been assigned to exactly one of the four categories.
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 share of revenue is suggested as normal or acceptable.
- No multiplier is applied for hidden or unmeasured quality costs.
- Amounts are shown in the currency selected; no exchange rate is applied.
Limitations
- Only the costs entered are included; costs not recorded by the organisation are absent from the total.
- Category boundaries vary between organisations, which limits comparison with anyone else's figures.
- A measured cost of quality, an industry benchmark and an organisation's target are three different things.
Source and version
- Standard or reference
- Cost of quality — prevention, appraisal and failure model — ASQ (ASQ cost of quality: quality costs are grouped as prevention, appraisal, internal failure and external failure.)
- 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.
Related tools
Work out the hourly rate to charge a client so that target margin is met after overhead and non-billable time.
Find the true hourly cost of an employee once benefits, payroll cost and overhead are included.
Size a software application from its data and transaction functions before estimating effort or cost.
Estimate development effort, schedule and average team size for a software project of a known size.
Express cloud spend as a cost per customer, per transaction or per other business unit.
Set the rate used to apply manufacturing overhead to jobs for the coming period.