A supplement labelled 500 mg of a mineral compound does not give you 500 mg of the mineral. Most of that weight is the carrier the mineral is bonded to.

Pick the form below, or enter your own percentage from the label, and the calculator returns the elemental amount, the number that actually counts toward your intake.

Two weights, one capsule

Minerals in supplements are bonded to a carrier, so the compound weight and the elemental weight are two different numbers.

Elemental mineral (mg) = compound amount (mg) × (elemental % ÷ 100)

50 mg of zinc picolinate at about 21% elemental zinc gives about 10.5 mg of zinc. A 500 mg magnesium glycinate capsule at about 14% gives about 70 mg of elemental magnesium.

Compare the elemental number

The elemental figure is the one that counts toward your daily intake. A good Supplement Facts panel already states it, for example Magnesium (as magnesium glycinate) 70 mg.

Two products can list the same compound weight and deliver very different elemental amounts if their forms differ. Compare elemental figures, not front-label compound weights.

The presets are typical, not exact

The percentages are approximate, because the exact elemental content varies with the hydration state and the specific salt. Where a label gives an exact elemental amount, trust that over the preset.

Elemental is also not the same as absorbed. Higher elemental content does not make a better product, since some high-percentage forms are absorbed less well. The Bioavailability Calculator looks at what helps each supplement absorb.

What to do with the number

Once you have the elemental amount, the Daily Value (%DV) Calculator shows how it compares with the daily reference. If you take more than one product, the Upper Limit Checker adds the mineral up across all of them, using the elemental amounts.

For magnesium on its own, the Magnesium Dosage Calculator goes further, and the Cost Per Dose Calculator shows what each real dose costs. This tool assumes the label figures are correct and does no measuring of its own.

Where this comes from

Government fact sheets confirm that supplement labels declare the elemental amount of a mineral, not the weight of the whole compound. See the NIH Office of Dietary Supplements magnesium fact sheet.

The same office publishes the zinc fact sheet.

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.