Based on ANSI/ASQ Z1.4 single sampling (normal inspection). Enter your lot size and AQL levels to get sample size n and accept / reject numbers.
After you have the sample size, book an Amazon FBA inspection in China so the same AQL plan is applied at the factory before shipment.
For reference only. Final sampling plans should match your purchase order, contract, or inspection scope. CloudSpects uses ANSI/ASQ Z1.4 by default on pre-shipment inspections unless otherwise agreed. 结果仅供参考；实际抽样方案以合同或验货范围为准。CloudSpects 出货前检验默认采 - ANSI/ASQ Z1.4，除非另有约定 参考値です。実際のサンプリングは契約・検査範囲に従います。CloudSpects - PSI は原 - ANSI/ASQ Z1.4 を使用します
Need the same plan on site? China inspection from $169/man-day, English photo report typically ~24h.
Book an inspection 预约验货 検品を予 Inspection standards 检验标准说 検査基準An AQL calculator does not invent a new standard. It looks up the same ANSI/ASQ Z1.4 single-sampling plan a China inspector uses on a finished lot. You enter three facts: how many units are ready, which general inspection level you want (Level II is the default for consumer goods), and the AQL for each defect class. The tool returns sample size n plus the accept (Ac) and reject (Re) numbers.
Worked example: a 2,000-unit electronics lot, Level II, critical AQL 0, major AQL 2.5, minor AQL 4.0. The lot sits in the 1,201–3,200 band, code letter K. The calculator should show n = 125. At major AQL 2.5 the plan is Ac 7 / Re 8. That means 7 major defects in the 125-piece sample still pass; the 8th major defect fails the lot. Critical defects use a tighter row — often Ac 0 / Re 1 — because one safety or regulatory fail is enough to stop shipment.
Use the numbers before you book, not after the inspector is already in the factory. If the sample size surprises you (a 10,000-unit lot still only draws 200 pieces at Level II), that is the standard working as designed. If you need more coverage, switch to Level III or add a tightened plan on the SKUs that failed last time. Then send the same lot size and AQL levels to your Amazon FBA inspection booking so the on-site check matches the calculator.
Ac is the acceptance number: the largest count of defects, in that class, that still lets the lot pass. Re is the rejection number: one more defect than Ac, and the lot fails. They always sit one integer apart on a single-sampling plan (Ac 5 / Re 6, Ac 7 / Re 8). The inspector does not average them, and does not “give a second chance” inside the same sample unless you contracted a double-sampling plan.
Read Ac/Re per class, not as a pile of all defects. A lot can pass major AQL 2.5 and still fail on critical AQL 0 if one unit has a banned substance, a crush hazard, or a missing required warning. Minor defects (scuffs, light cosmetic marks) use a looser AQL, commonly 4.0, so they do not fail a shipment that is commercially acceptable.
CloudSpects writes Ac/Re on the English photo report with the code letter and sample size. If you only remember one rule: do not release final payment when Re is reached in any class you care about. That is the point of running the calculator before the visit.
The table below is the major-defect AQL 2.5 row importers ask for most often. It is a CloudSpects working snapshot of ANSI/ASQ Z1.4 Level II, not a substitute for the full published standard. Enter the same lot size above to see critical and minor rows as well.
| Lot size band | Code | Sample size n | Major AQL 2.5 (Ac / Re) |
|---|---|---|---|
| 151 – 280 | G | 32 | 2 / 3 |
| 281 – 500 | H | 50 | 3 / 4 |
| 501 – 1,200 | J | 80 | 5 / 6 |
| 1,201 – 3,200 | K | 125 | 7 / 8 |
| 3,201 – 10,000 | L | 200 | 10 / 11 |
Same 2,000-unit example: band K, n 125, Ac 7 / Re 8 at major AQL 2.5. A 500-unit lot drops to n 50 and Ac 3 / Re 4. That is why “inspect 10%” is not an AQL plan — percent sampling does not follow the code-letter table.
Read next: how to read an AQL table and choose sample size, how to calculate sample size and acceptance number, and AQL 1.0 vs 2.5 vs 4.0.
Yes. The CloudSpects AQL calculator is free to use in the browser. It applies ANSI/ASQ Z1.4 single normal sampling and does not require an account.
Most general consumer goods use critical AQL 0, major AQL 2.5, and minor AQL 4.0 at Level II. Tighten major to 1.0 when the SKU has a history of function fails, sharp edges, or costly FBA inbound defects.
No. Z1.4 sample sizes step up by code letter, not by a fixed percentage. A 10,000-unit lot at Level II is still 200 pieces. If you need more coverage, change the inspection level or AQL rather than inventing a 10% rule.
The lot fails that defect class. You can hold final payment, ask the factory to rework or sort, then book a re-inspection. CloudSpects records the fail on the English photo report so the decision is evidence-based.
Yes. CloudSpects uses ANSI/ASQ Z1.4 by default on pre-shipment inspections unless the purchase order says otherwise. Run the numbers here, then book the visit on the China pre-shipment inspection page.
The AQL is the quality level considered acceptable as a process average. AQL 1.0 is tighter (smaller Ac for the same sample), 2.5 is the usual major-defect default, and 4.0 is common for minor cosmetics. Sample size n does not change when you only change AQL — Ac and Re do.
Standard China inspections start from $169 per man-day, and the English photo report is typically ~24h after the visit. Share lot size, AQL, factory city, and preferred date on the contact form.
No. It is a working lookup for the single-sampling plans we use on typical lots. Contracts, government tenders, or medical/automotive programs may require a different code letter, switching rules, or a published table excerpt attached to the PO.