AQL SAMPLING CALCULATOR BY SYMESTIC

AQL Sampling Calculator

Find sample size, acceptance number and rejection number for a normal single sampling plan. The calculator uses public-domain Tables I and II-A of MIL-STD-105E, dated 1989.

Guide FAQ

Your inputs

Lot size

parts

Whole number of at least 2 parts in the lot to inspect.

General inspection level

Level II is preset. Use the level required by your inspection agreement.

AQL

Supported table values: 0.65, 1, 1.5, 2.5, 4 and 6.5.

Inspection size

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Acceptance number Ac

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Rejection number Re

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Share of lot

–

Table size before full inspection

–

Breakdown

Review scenarios

Changing inspection level changes the plan and workload. Follow the inspection agreement. Sample-plan Ac and Re do not apply to full inspection.

Inspection level III: inspection size

Inspection level I: inspection size

Recommendations

Draw a random sample across the whole lot. Count nonconforming units for each agreed defect class. Accept under the plan at Ac or below; reject at Re or above. For full inspection, follow agreed sorting and rework rules.

PPM Calculator

AQL Sampling Calculator: Guide

Choose lot and inspection level

Enter a whole-number lot size. Follow the general inspection level in your inspection agreement.

Set AQL

Choose one of the six supported AQL values. The calculator follows table arrows to the valid plan.

Read the plan

Table I gives the code letter. Table II-A gives sample size and Ac/Re. When the plan reaches the whole lot, the calculator shows full inspection.

The formulas at a glance

Code letter

Lot size + inspection level → Table I

General inspection levels I, II and III.

Sampling plan

Code letter + AQL → Table II-A

Arrows may change sample size. Ac and Re are table lookups, never AQL × sample size.

Lot decision

Nonconforming units ≤ Ac; reject at Re

Applies to the sampling plan shown, excluding full inspection.

Worked example: a lot of 1,000 parts

For 1,000 parts, general inspection level II and AQL 2.5, the code letter is J. The normal single sample contains 80 parts, with Ac = 5 and Re = 6.

Item	Calculation	Result
Code letter	501 to 1,200, level II	J
Sample	J, AQL 2.5	80 parts
Acceptance number	Table II-A	5
Rejection number	Table II-A	6

Limits of the calculation

Normal single sampling for nonconforming units only, general levels I to III and the six selectable AQL values. Special levels, tightened and reduced inspection are excluded.
MIL-STD-105E is a historical, withdrawn standard. This calculator does not demonstrate compliance with current ISO 2859-1. No ISO tables are used.
AQL is distinct from an allowable defect percentage for each lot. Poor-quality lots may still be accepted. Switching rules for a continuing series of lots are excluded.
When table sample size reaches lot size, inspect the whole lot. Sample-plan Ac/Re no longer apply; follow the inspection agreement for nonconforming parts.

Frequently asked questions

How is AQL sample size calculated?

Lot size and inspection level give a code letter in Table I. Code letter and AQL lead to the plan in Table II-A. Table arrows must be followed.

What do Ac and Re mean?

Ac is the highest number of nonconforming units in the sample for acceptance. Re is the number at which the lot is rejected.

Is AQL an allowed defect percentage?

AQL is a quality level used to assess a continuing series of lots. It does not guarantee a maximum defect percentage in an accepted lot.

Which standard does this calculator use?

Public-domain tables from MIL-STD-105E, dated 1989. Current contractual or industry-specific requirements need separate review.

Why can the sample exceed the code-letter size?

An arrow in Table II-A refers to another plan. The calculator shows both original and effective code letters.

Calculation source: MIL-STD-105E (1989), Table I, Table II-A, 4.9.3