Supplement labels often show a herbal extract and a standardisation percentage, but not the amount of active compound you actually get. Enter the two numbers from the label below and this tool returns the milligrams of the marker compound per serving, plus your daily total if you take more than one serving.

How this works

The math is a direct conversion. A standardised extract is processed so that a set percentage of it, by weight, is a chosen marker compound. So the active compound per serving is:

Active compound (mg) = extract amount (mg) × (standardisation % ÷ 100)

For example, 500 mg of a turmeric extract standardised to 95% curcuminoids gives 500 × 0.95 = 475 mg of curcuminoids per serving. The daily total is that figure multiplied by the number of servings.

Understanding your result

The number is the amount of the marker compound, not the whole extract. This is the figure worth comparing between products, because two products with the same extract weight can deliver very different amounts of the active compound when their standardisation percentages differ. When you check a product against a study, compare the study's dose to this active-compound figure, not to the raw extract weight.

Important limitations

• A marker compound is not always the compound responsible for the effect. Standardisation guarantees a consistent amount of one measured substance, which may or may not be the active one.
• The percentage on the label is only as reliable as the testing behind it. A third-party certificate of analysis is what confirms the number is real.
• This tool assumes the label figures are correct. It does no measuring of its own.
• The amount absorbed can differ from the amount present, since absorption depends on the compound and its formulation.

Scientific basis

A standardised extract is defined by the percentage of a marker compound it contains by weight, verified by laboratory assay. These sources explain the concept and its limits:

• Marker compounds used for herbal medicine standardisation (National Library of Medicine)
• Determination of marker compounds in a herbal extract (National Library of Medicine)

This calculator is for general education only and is not medical or professional advice. Always check product labels and speak with a qualified professional before making decisions about supplements.