Inspection tools

AQL calculator

Enter the order quantity and the AQL your buyer uses. The sample size and the accept and reject numbers update as you type.

Order quantity

Number of units in the lot or shipment.

Sample size

Code letter

Defect	Sample	Accept up to	Reject at

Single sampling, normal inspection, per ISO 2859-1 / ANSI/ASQ Z1.4. Check your buyer’s QA manual for the plan that applies to your order.

Inspection level

Critical

Major

Minor

Starting values are common for furniture (Level II, critical 0, major 2.5, minor 4.0). Your buyer or retailer may set different ones.

How to read the tables, step by step

The steps use the numbers you entered above. Each cell they point to is highlighted in the tables below.

Find your quantity in Table I. 1,000 units falls in the 501 to 1,200 row.
Move across to your inspection level. Level II points to code letter J.
Find that letter in Table II. Row J has a sample size of 80 pieces.
Move across to the AQL for each defect class. Major, AQL 2.5: accept 5, reject 6. Minor, AQL 4.0: accept 7, reject 8.
If you land on an arrow, follow it. Go to the first number in the arrow’s direction and use the sample size of that row instead. None of your classes land on an arrow.
Inspect and count. Pull the sample at random from the whole lot and count defects by class. A class that reaches its reject number fails the lot. Critical is set to 0, so one critical defect fails it.

Table I. Sample size code letters
Lot size	I	II	III	S1	S2	S3	S4
2 to 8	A	A	B	A	A	A	A
9 to 15	A	B	C	A	A	A	A
16 to 25	B	C	D	A	A	B	B
26 to 50	C	D	E	A	B	B	C
51 to 90	C	E	F	B	B	C	C
91 to 150	D	F	G	B	B	C	D
151 to 280	E	G	H	B	C	D	E
281 to 500	F	H	J	B	C	D	E
501 to 1,200	G	J	K	C	C	E	F
1,201 to 3,200	H	K	L	C	D	E	G
3,201 to 10,000	J	L	M	C	D	F	G
10,001 to 35,000	K	M	N	C	D	F	H
35,001 to 150,000	L	N	P	D	E	G	J
150,001 to 500,000	M	P	Q	D	E	G	J
500,001 and over	N	Q	R	D	E	H	K

Table II-A. Single sampling, normal inspection (Ac / Re)
Code · sample	0.065	0.10	0.15	0.25	0.40	0.65	1.0	1.5	2.5	4.0	6.5
A2	↓	↓	↓	↓	↓	↓	↓	↓	↓	↓	0 / 1
B3	↓	↓	↓	↓	↓	↓	↓	↓	↓	0 / 1	↑
C5	↓	↓	↓	↓	↓	↓	↓	↓	0 / 1	↑	↓
D8	↓	↓	↓	↓	↓	↓	↓	0 / 1	↑	↓	1 / 2
E13	↓	↓	↓	↓	↓	↓	0 / 1	↑	↓	1 / 2	2 / 3
F20	↓	↓	↓	↓	↓	0 / 1	↑	↓	1 / 2	2 / 3	3 / 4
G32	↓	↓	↓	↓	0 / 1	↑	↓	1 / 2	2 / 3	3 / 4	5 / 6
H50	↓	↓	↓	0 / 1	↑	↓	1 / 2	2 / 3	3 / 4	5 / 6	7 / 8
J80	↓	↓	0 / 1	↑	↓	1 / 2	2 / 3	3 / 4	5 / 6	7 / 8	10 / 11
K125	↓	0 / 1	↑	↓	1 / 2	2 / 3	3 / 4	5 / 6	7 / 8	10 / 11	14 / 15
L200	0 / 1	↑	↓	1 / 2	2 / 3	3 / 4	5 / 6	7 / 8	10 / 11	14 / 15	21 / 22
M315	↑	↓	1 / 2	2 / 3	3 / 4	5 / 6	7 / 8	10 / 11	14 / 15	21 / 22	↑
N500	↓	1 / 2	2 / 3	3 / 4	5 / 6	7 / 8	10 / 11	14 / 15	21 / 22	↑	↑
P800	1 / 2	2 / 3	3 / 4	5 / 6	7 / 8	10 / 11	14 / 15	21 / 22	↑	↑	↑
Q1,250	2 / 3	3 / 4	5 / 6	7 / 8	10 / 11	14 / 15	21 / 22	↑	↑	↑	↑
R2,000	3 / 4	5 / 6	7 / 8	10 / 11	14 / 15	21 / 22	↑	↑	↑	↑	↑

↓ use the first plan below the arrow. ↑ use the first plan above it. If the sample size equals or exceeds the lot size, inspect every piece. Lots over 500,000 all use the last row of Table I.

What counts as critical, major or minor

The AQL numbers only work when everyone uses the same defect definitions. Our furniture defect classification is the reference we work from, and how AQL sampling actually works in furniture inspection explains what a pass does and doesn’t tell you.

A sampling plan is only as good as the inspection behind it. See how we run inspections on the line.