AQL Calculator & Ultimate ISO 2859-1 Guide
The essential tool for quality control inspections. Instantly determine sample sizes and acceptance limits to secure your supply chain.
Calcolatore AQL (Limite di Qualità Accettabile)
Determina la dimensione del campione e i limiti di accettazione/rifiuto.
*Il livello II è standard per la maggior parte delle ispezioni.
Inserisci la dimensione del lotto per vedere i risultati.
What is AQL (Acceptable Quality Limit)?
AQL, or "Acceptable Quality Limit", represents the maximum allowable number of defects in a batch of goods undergoing inspection. The global standard is ISO 2859-1. It helps B2B buyers validate the quality of tens of thousands of products without having to check every single item (which would be prohibitively expensive).
The 3 Types of Defects
Critical Defects
AQL Standard: 0.0. ZERO tolerance. These defects make the product unsafe for the user, violating safety norms or local laws. Example: needles left in clothing, exposed wires in electronics.
Major Defects
AQL Standard: 2.5. These defects are not dangerous but significantly affect the functionality or salability of the product. The product would be rejected by the final customer. Example: a broken zipper, a large stain on the fabric.
Minor Defects
AQL Standard: 4.0. These defects are small visual imperfections that do not affect the use of the product and that most customers would not notice. Example: an uncut thread on the inside, a slight color variation.
How to read the AQL Tables (Methodology)
Traditionally, inspectors use two main tables. The first table is used to find the "Sample Size Code Letter" based on your total Lot Size and the chosen inspection level (usually General Level II).
The second table tells you, based on that letter, how many products you need to randomly extract (Sample Size) and how many defects of a certain type are allowed before the batch is Rejected (Fail). Our calculator above completely automates both tables!
What do the Inspection Levels (I, II, III) mean?
- Level I (Relaxed): Used when the factory has a very good track record and you trust them implicitly. You extract fewer samples.
- ⭐ Level II (Standard): This is the default setting for 98% of inspections worldwide. It offers the best balance between statistical safety and inspection cost.
- Level III (Strict): Used for luxury goods, medical devices, or when the factory has a history of poor quality. You extract a large number of samples.
Theory is simple, Execution is hard
Finding out from the calculator that you need to check 315 pieces and allow a maximum of 14 major defects is easy. The hard part is having an inspector in the factory who won't be fooled by the supplier, who TRULY randomly extracts samples from the back of the warehouse, and objectively identifies defects. At Marystelv, we protect European buyers by executing strict on-site inspections.