AQL Sampling Calculator — Quality Inspection Sample Size

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)

Accept/Reject Numbers at AQL 2.5

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?

AQL Best Practices for China Importers

1. 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.

2. 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."

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.