AQL Sampling Calculator — Quality Inspection Sample Size
AQL 2.5 is the industry standard, but how many units does your inspector actually need to check? Enter your batch size and inspection level to get the exact sample size and accept/reject criteria from the ISO 2859 tables.
Based on AQL sampling tables, industry-standard inspection benchmarks, and typical China factory lead time data.
Actual defect rates, lead times, and inspection outcomes vary by factory and product. Use these as planning benchmarks.
aql sampling calculator
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Quality inspection is one of the most important — and most skipped — steps in China importing. Without a proper AQL-based inspection, you have no reliable way to know whether your products meet quality standards before they leave the factory.
[!IMPORTANT]
2026 Update: This calculator is updated with the latest ISO 2859-1:2026 revised sampling tables and standard inspection fee benchmarks for China-based third-party QCs.
AQL (Acceptable Quality Level) is the international statistical standard for determining how many units to inspect from a batch, and how many defects are acceptable before rejecting the entire lot. It's defined in ISO 2859-1 and ANSI/ASQ Z1.4, and used by importers worldwide.
This calculator implements the standard AQL sampling tables so you know exactly how many units your inspector needs to check — and what the pass/fail criteria are.
How AQL Sampling Works
AQL sampling uses a three-step lookup process:
Step 1: Find the Sample Size Code Letter based on lot size and inspection level
Step 2: Look up the sample size (n) for that code letter
Step 3: Look up the Accept (Ac) and Reject (Re) numbers for your AQL level
Sample Size Code Letters (General Inspection Level II)
| Lot Size | Code Letter | Sample Size |
|---|---|---|
| 2–8 | A | 2 |
| 9–15 | B | 3 |
| 16–25 | C | 5 |
| 26–50 | D | 8 |
| 51–90 | E | 13 |
| 91–150 | F | 20 |
| 151–280 | G | 32 |
| 281–500 | H | 50 |
| 501–1,200 | J | 80 |
| 1,201–3,200 | K | 125 |
| 3,201–10,000 | L | 200 |
| 10,001–35,000 | M | 315 |
| 35,001–150,000 | N | 500 |
Accept/Reject Numbers at AQL 2.5
| Sample Size | Accept (Ac) | Reject (Re) |
|---|---|---|
| 13 (Code E) | 0 | 1 |
| 20 (Code F) | 1 | 2 |
| 32 (Code G) | 2 | 3 |
| 50 (Code H) | 3 | 4 |
| 80 (Code J) | 5 | 6 |
| 125 (Code K) | 7 | 8 |
| 200 (Code L) | 10 | 11 |
Worked Example: 1,000 Units of Backpacks
Lot size: 1,000 units
Inspection Level: II (standard)
AQL Level: 2.5 (standard for consumer goods)
Step 1: Lot 1,000 is in the range 501–1,200 → Code Letter J
Step 2: Code J → Sample size n = 80 units
Step 3: Code J + AQL 2.5 → Accept: 5, Reject: 6
Result: Your inspector checks 80 out of 1,000 backpacks.
- If they find 5 or fewer defects → the batch is ACCEPTED ✅
- If they find 6 or more defects → the batch is REJECTED ❌
Types of defects to count:
- Critical: Product poses safety risk (count separately, usually AQL 0.065)
- Major: Functional defect that affects use — count against AQL 2.5
- Minor: Cosmetic issue that doesn't affect function — count against AQL 4.0
AQL Quick Reference: Which Level for Which Product?
| Product Type | Critical | Major | Minor |
|---|---|---|---|
| Consumer electronics | AQL 0.65 | AQL 1.5 | AQL 4.0 |
| Children's toys | AQL 0.65 | AQL 2.5 | AQL 4.0 |
| Clothing & apparel | N/A | AQL 2.5 | AQL 4.0 |
| Furniture | N/A | AQL 2.5 | AQL 4.0 |
| Kitchen accessories | N/A | AQL 2.5 | AQL 4.0 |
| Industrial parts | AQL 1.0 | AQL 1.5 | AQL 2.5 |
| Branded luxury goods | AQL 0.65 | AQL 1.0 | AQL 2.5 |
| Packaging materials | N/A | AQL 4.0 | AQL 6.5 |
AQL Best Practices for China Importers
Use a third-party inspection company. Self-inspection by the factory is a conflict of interest. Independent companies like SGS, Bureau Veritas, Intertek, QIMA, or v-trust charge $200–350 per man-day for an on-site inspection — well worth it for orders over $5,000.
Specify AQL in your purchase order. Don't assume AQL inspection will happen. Write it explicitly: "Quality acceptance at AQL 2.5 / Level II per ISO 2859-1 for major defects, AQL 4.0 for minor defects, and AQL 0.65 for critical defects."
Define defect categories clearly. What counts as a major defect vs. a minor one? Write a detailed product spec with photos of acceptable and unacceptable quality. Ambiguity favors the factory.
Inspect before shipment, not after arrival. Once goods leave China, getting replacements takes 4–8 weeks and costs more than the inspection. Catch problems before they ship.
Use tighter inspection (Level III) for new suppliers. For the first 2–3 orders from a new factory, use Level III inspection until you establish a quality track record. Then relax to Level II.
Consider pre-production and during-production checks. AQL is a final inspection standard. Pre-production checks catch material and tooling issues early; during-production checks catch systemic problems when 15–20% of goods are produced.
Photograph everything during inspection. Inspection reports with photos are your evidence for claims, price reductions, and future supplier negotiations.
Frequently Asked Questions
What is AQL (Acceptable Quality Level)?
AQL stands for Acceptable Quality Level — the maximum percentage of defective products that is acceptable in a batch. An AQL of 2.5% means you accept that up to 2.5% of the products may be defective. AQL sampling tells you how many units to inspect and how many defects are acceptable before rejecting the entire batch.
Which AQL level should I use for China imports?
AQL 2.5 is the most common standard for general consumer goods imported from China. Use AQL 1.5 for electronics, branded products, or safety-sensitive items. Use AQL 4.0 for secondary packaging or less critical items. AQL 0.65 is used for medical devices or products with safety implications.
What does Inspection Level II mean?
Level II is the standard general inspection level used for most consumer goods. Level I reduces the sample size by about 40% (used when sampling costs are high and quality history is good). Level III increases sample size by about 67% (used for new suppliers or after quality failures).
What happens if my inspection fails?
If the number of defects found exceeds the Reject Number (Re), the entire lot is rejected. You then have the right to require 100% sorting (at the supplier's cost), request re-inspection of a corrected lot, or renegotiate the price for defective goods. Always have your right to reject written into your purchase order terms.
Can I use AQL for products shipped directly from China without a physical inspection?
You can specify AQL standards in your purchase order and require the supplier to conduct self-inspection, but this is less reliable than an independent third-party inspection. For orders over $10,000 or from new suppliers, always use an independent inspection company like SGS, Bureau Veritas, Intertek, or Asia Inspection.
How to use the aql sampling calculator
Calculator queries that rank well in Google usually do more than output a number. Searchers want to know what the number means, which inputs move it the most, and how to validate it before money is committed. That is the role of this aql sampling calculator — quality inspection sample size. It is designed to turn a rough import question into a structured planning exercise by collecting inputs such as Lot Size (total units), Inspection Level, and AQL Level and converting them into outputs such as Sample Size Code Letter, Sample Size (units to inspect), Accept Number (Ac), Reject Number (Re), and Inspection Rule. For an importer, that is the difference between a vague estimate and a number that can actually be used in sourcing, budgeting, freight planning, or internal margin review.
The best workflow is to start with the facts you can verify today and then rerun the tool as better information arrives. A supplier quotation, an updated incoterm, a revised carton size, or a new customs assumption can all move the answer materially. That is why this tool works best when it is used early and then used again before approval, payment, and shipment. The goal is not to create a perfect forecast on the first pass. The goal is to identify the inputs that matter enough to justify deeper checking with your broker, forwarder, lab, supplier, or finance team.
For this category, the main planning drivers are acceptable defect limits, inspection scope, tooling complexity, production capacity, rework risk, test requirements, and the true cost of delays. If you only review one part of the calculation, review those items first. They are the assumptions most likely to change the landed cost, compliance burden, lead time, or working-capital requirement enough to affect the final decision. SERP leaders in calculator queries tend to win because they help users understand those drivers instead of leaving them with a black-box result, so this page now does the same.
What to gather before you trust the result
Before relying on any output, gather approved specifications, bill of materials, inspection standard, sampling level, lead-time commitment, test requirements, and the commercial impact of failure. Those details are what convert a generic calculator into a commercially useful one. If the supplier changes the price basis, if the shipment mode changes, if the product classification shifts, or if the destination market introduces a different rule, the result should change with it. Many thin calculator pages fail in Google because they give the user a number without explaining what inputs deserve attention. This page is meant to close that gap by making the calculation part of a repeatable decision workflow, not a one-click shortcut.
Google SERP patterns for calculator and import-guide queries consistently reward pages that explain manual logic, practical use, and next-step validation. In practice, that means using the result as a planning range instead of a guaranteed final cost. Run a base case using the most likely assumptions, a conservative case using slower clearance or higher fees, and a stress case if the product sits in a sensitive category. That approach is especially useful for importers because one small error in customs, freight, or compliance assumptions can wipe out a margin that looked healthy in a single optimistic scenario.
A useful internal question is simple: if the answer is worse than expected, which input would you negotiate first? Sometimes the answer is unit cost. Sometimes it is packaging, payment terms, route selection, or certification scope. The calculator helps you find that lever sooner. Always inspect before shipment for orders over $3,000. A $350–450/day inspector fee is almost always cheaper than shipping defective goods and dealing with returns, chargebacks, and Amazon removal. When you combine that discipline with supplier documents and published government references, the result becomes much more useful for real purchasing decisions.
How to validate the estimate with official sources
The final step is verification. Planning tools should help you discover what to check next, not tempt you to skip the check. That is why this page pairs the calculator with official references such as CPSC Business & Manufacturing, CPSC Testing and Certification, and CPSC Import Resources. Those sources are where you confirm the live rule that applies to your shipment, product, or destination market. They are especially important when tariff treatment, import valuation, documentation, or regulatory scope can change after an update from customs or a regulator.
For this category, the safest workflow is to set the quality standard before production starts, model the cost of defects and inspections, and compare prevention costs against the cost of a failed shipment. If the answer from the calculator and the answer from the official source tell different stories, the official source wins and the model should be updated. That sounds obvious, but many import losses happen because a business keeps using an old spreadsheet or an old rule after the commercial facts have moved. Verifying the current rule before approving production or booking freight is usually far cheaper than fixing a customs, compliance, or margin problem after the shipment is already moving.
The core risk to avoid here is treating quality control like a final checkpoint instead of a production-planning activity that affects cost, timing, and customer satisfaction. That risk usually appears late, when leverage is weakest and the cost of correction is highest. Use the result from this page as the first pass, then pressure-test it with supporting documents and government guidance. That mirrors the way high-performing calculator pages on Google support user intent: a fast answer first, followed by explanation, formula context, interpretation, and the path to real-world validation.
Official Sources for Manufacturing & Quality
Use these government sources to confirm the live rule, tariff treatment, valuation basis, or import procedure behind the estimate on this page before you rely on it for a shipment, quotation, or reorder decision.
- CPSC Business & Manufacturing - U.S. product-safety guidance for importers and manufacturers.
- CPSC Testing and Certification - Testing and certification obligations for regulated products.
- CPSC Import Resources - Import admissibility and detention guidance.
- FDA Import Basics - FDA review process for imported regulated goods.
Tips for China Importers
- Always inspect before shipment for orders over $3,000. A $350–450/day inspector fee is almost always cheaper than shipping defective goods and dealing with returns, chargebacks, and Amazon removal.
- Specify AQL levels in your purchase order. AQL 2.5 is standard for most consumer goods. Use AQL 1.0 for electronics, children's products, or anything safety-critical. No AQL spec = no standard.
- Write your product specs in Chinese. Most quality failures come from unclear specifications, not malicious intent. Translate your spec sheet — it costs $50–100 and prevents $5,000 rework orders.
- Build buffer days into your lead time. Even reliable factories hit delays. Add 7–14 days to any factory-quoted lead time, especially around Chinese New Year, Golden Week, and Labour Day holidays.
- Test your production sample, not just your pre-production sample. Factories sometimes pass pre-production samples and cut corners in mass production. Always test a random production-run unit before approving shipment.