AQL Sampling Plan.
ANSI/ASQ Z1.4 and ISO 2859-1 single sampling plan. Enter your lot size and Acceptable Quality Level — get sample size, acceptance number, and rejection number for incoming or outgoing inspection.
Total quantity in the inspection lot
Level II is the default for most quality plans
Maximum allowable defect rate the customer accepts
Sample Size
—
Pieces to inspect
Accept (Ac)
—
Defects: pass
Reject (Re)
—
Defects: fail
Decision rule
Inspect — randomly selected pieces from the lot of —.
If — or fewer defects are found → ACCEPT lot.
If — or more defects are found → REJECT lot.
If — or fewer defects are found → ACCEPT lot.
If — or more defects are found → REJECT lot.
Code letter (sample size code)
—
Sample size code letters (Level II — default)
| Lot size | S-1 | S-2 | S-3 | S-4 | Level I | Level II | Level III |
|---|---|---|---|---|---|---|---|
| 2 to 8 | A | A | A | A | A | A | B |
| 9 to 15 | A | A | A | A | A | B | C |
| 16 to 25 | A | A | B | B | B | C | D |
| 26 to 50 | A | B | B | C | C | D | E |
| 51 to 90 | B | B | C | C | C | E | F |
| 91 to 150 | B | B | C | D | D | F | G |
| 151 to 280 | B | C | D | E | E | G | H |
| 281 to 500 | B | C | D | E | F | H | J |
| 501 to 1,200 | C | C | E | F | G | J | K |
| 1,201 to 3,200 | C | D | E | G | H | K | L |
| 3,201 to 10,000 | C | D | F | G | J | L | M |
| 10,001 to 35,000 | C | D | F | H | K | M | N |
| 35,001 to 150,000 | D | E | G | J | L | N | P |
| 150,001 to 500,000 | D | E | G | J | M | P | Q |
| 500,001 and over | D | E | H | K | N | Q | R |