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Content Uniformity Calculator: Acceptance Value (AV) per USP <905>
Calculate the acceptance value (AV) for uniformity of dosage units from the assay of each tablet or capsule, or from weight variation, and see whether the batch passes Stage 1 (10 units) or Stage 2 (30 units). Follows the harmonised USP <905> / Ph. Eur. 2.9.40 method. Free, with a printable record.
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How it works
k = 2.4 for 10 units, 2.0 for 30 units
M = X̄ if 98.5 % ≤ X̄ ≤ 101.5 %; M = 98.5 % if X̄ < 98.5 %; M = 101.5 % if X̄ > 101.5 % (target T ≤ 101.5 %)
Weight variation: content of unit = weight × assay % ÷ mean weight
| Stage | Units | Acceptance |
|---|---|---|
| Stage 1 | 10 | AV not more than L1 = 15.0 |
| Stage 2 | 30 (10 + 20) | AV of 30 not more than 15.0, and no unit outside (1 − 0.25) M to (1 + 0.25) M |
Worked example
10 tablets, mean 99.95 %
Contents 98.2, 101.5, 99.6, 97.8, 100.9, 102.3, 99.1, 98.7, 100.4 and 101.0 % give X̄ = 99.95 % and s = 1.50. X̄ is between 98.5 and 101.5 %, so M = X̄ and AV = 2.4 × 1.50 = 3.6 – well within 15.0, so Stage 1 passes.
Weight variation may replace content uniformity only where the pharmacopoeia allows it – typically when the unit contains 25 mg or more of the drug and the drug is 25 % or more of the unit by weight. Check your monograph.
Frequently asked questions
What is a good acceptance value?
Anything up to 15.0 passes Stage 1. Well-made tablets usually give an AV between 2 and 8. A high AV comes from a large spread (s) or a mean far from 100 %.
What if my target T is more than 101.5 %?
Some monographs set a target above 101.5 % for products with an overage. Enter that value as T: M then equals X̄ up to T, and T above it, as in the pharmacopoeial table.
Is this the IP test?
The acceptance-value method is the harmonised USP <905> / Ph. Eur. 2.9.40 test. The Indian Pharmacopoeia includes it as a general chapter that is not mandatory unless a monograph refers to it; most IP monographs still use their own uniformity of content (85–115 % of the average) or uniformity of weight tests. Follow your monograph and use this calculator for USP/Ph. Eur. markets.
Can I use results expressed in mg?
Enter results as % of label claim. To convert, divide each result in mg by the label claim and multiply by 100.


