What is AQL?

AQL stands for Acceptable Quality Limit (also called Acceptable Quality Level). It is the worst average defect rate that a buyer and supplier agree is tolerable for an order. Because checking every garment is slow and costly, inspectors examine a random sample from the lot and count the defects. If the count stays within the plan's accept number, the lot passes. If it reaches the reject number, the lot fails.

The sampling tables used worldwide come from ISO 2859-1, which is technically aligned with ANSI/ASQ Z1.4 (descended from the military standard MIL-STD-105). This calculator uses the single sampling plans for normal inspection.

Why AQL matters in fashion and textiles

A shared standard. Buyer and factory agree in advance what counts as a pass, which prevents disputes after goods are produced.
Catches problems before shipping. Finding defects at the factory is far cheaper than finding them in your warehouse or in customer returns.
Practical for large orders. Apparel is made in thousands of identical units, so a well-drawn sample gives a reliable picture of the whole lot.
Supports supplier management. Tracking results over several orders shows which factories are consistent.
Documents your decision. A recorded plan, sample and result supports claims, discounts or rework requests when something goes wrong.

Defect classes in garments

Defects are sorted into classes, and each class gets its own AQL. Agree on the definitions in writing, since they vary by brand.

Typical examples
Class	Meaning	Examples
Critical	Unsafe or illegal to sell. No defects accepted.	Broken needle or metal fragment in the garment, hazardous drawstrings or small parts on children's wear, missing legally required labels.
Major	Likely to make the product unsellable or be returned.	Holes, open or broken seams, stains that will not clean, wrong size or measurements out of tolerance, wrong color, faulty zipper or buttons.
Minor	A flaw that most customers would not return the item for.	Loose threads, slight stitch irregularity, light pressing creases, small removable spots.

Choosing AQL values

There is no single correct choice. These pairings are common starting points to discuss with your supplier:

Product tier	Critical	Major	Minor
Premium, children's wear	Not allowed	1.5	2.5
Standard apparel	Not allowed	2.5	4.0
Basic or promotional goods	Not allowed	4.0	6.5

A lower AQL is stricter and usually means a larger sample or a lower accept number. Inspection level II is the usual default. Level III is more discriminating (useful for a new supplier or high-risk product), and Level I is less so.

How to run a garment inspection

Timing. A final random inspection is commonly done when the order is finished and most of it (often at least 80%) is packed. Inline inspections during production catch problems earlier.
Define the lot. A lot should be uniform: the same style, materials and production run. Mixed styles should be inspected as separate lots.
Draw a random sample. Pull pieces from many cartons and across all sizes and colors, not just the top of the first cartons.
Inspect against a reference. Use the approved sample, tech pack, measurement spec and a defect list that everyone has agreed on.
Record everything. Count each defect by class, and take photos of anything that triggers a reject.
Decide in advance what a fail means. Typical outcomes are 100% sorting and rework by the factory followed by re-inspection, or a negotiated discount. Put the terms in your purchase order.

What AQL does and does not tell you

Passing does not guarantee the lot has fewer defects than the AQL percentage. Use the "chance of acceptance" table in the calculator to see how a plan behaves for lots with more defects than the AQL.
Failing does not always mean the lot is bad, but it tells you the sample showed more defects than the plan tolerates.
AQL checks the appearance and construction of finished goods. It does not replace laboratory tests (for example fiber content, colorfastness, flammability or restricted substances) or measurement checks against your spec. See our quality testing page for companies that provide those services.
Rolls of fabric are usually graded with a point system such as the 4-point system, not with AQL.

Frequently asked questions

Does AQL 2.5 mean 2.5% of my order can be defective?

Not exactly. AQL 2.5 means that a lot with about 2.5% defective pieces will usually pass. A lot with more can still pass by chance, and a lot with fewer can occasionally fail. The chance-of-acceptance table in the calculator shows the actual odds for your lot.

Why does the table sometimes give a different sample size than expected?

For some combinations of code letter and AQL, the standard's table has an arrow pointing to a neighboring plan. When that happens you use that plan's sample size and accept/reject numbers. The calculator follows these arrows and tells you when it does.

What if the sample size is larger than my lot?

The standard says to inspect 100% of the lot when the sample size equals or exceeds the lot size. The calculator handles this automatically.

What if the major and minor plans call for different sample sizes?

The two plans are separate. A common practice is to inspect the larger sample and judge each defect class against its own accept and reject numbers, but you should agree the method with your supplier or inspection company beforehand.

What about tightened and reduced inspection?

The standard includes switching rules that move to tightened inspection after repeated rejections and to reduced inspection after a long run of good lots. This calculator covers normal inspection, which is where most buyers start. It also covers General levels I to III, not the special levels (S-1 to S-4) that are used when testing is destructive or very costly.

See AQL charts to see if you like this format better than a calculator.

Related tools and resources

This tool is for planning and general guidance. It implements published sampling tables, and you should confirm the plan against the current standard and your contract before relying on it for a commercial decision. See our Legal page for terms of use.

AQL Inspection Sampling Calculator

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