Elemental Mineral Calculator
Find the real amount of zinc, magnesium, iron or calcium behind the compound weight on the label.
This tool was built by Serge (MSc) using established science and government sources. My academic background covers plant biology, environmental biology, and biogeochemistry. My tools are for educational purposes and give practical guidance, not professional advice.
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 this tool returns the elemental amount, the number that actually counts toward your intake.
How this works
Minerals in supplements are bonded to a carrier, so the compound weight and the elemental weight are two different numbers. The elemental amount is:
Elemental mineral (mg) = compound amount (mg) × (elemental % ÷ 100)
For example, 50 mg of zinc picolinate at about 21% elemental zinc gives 50 × 0.21 = about 10.5 mg of zinc. A 500 mg magnesium glycinate capsule at about 14% gives about 70 mg of elemental magnesium.
Understanding your result
The elemental figure is the number that counts toward your daily intake, and it is what a good Supplement Facts panel already states as, 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. So compare elemental figures, not front-label compound weights.
Important limitations
- The preset percentages are approximate. The exact elemental content varies with the hydration state and the specific salt used, so where a label gives an exact elemental amount, trust that over the preset.
- Elemental amount is not the same as absorbed amount. How much your body takes up also depends on the form and on other factors in the gut.
- This tool assumes the label figures are correct and does no measuring of its own.
- Higher elemental content does not mean a better product, since some high-percentage forms are absorbed less well.
Scientific basis
Government fact sheets confirm that supplement labels declare the elemental amount of a mineral, not the weight of the whole compound:
- Magnesium fact sheet, NIH Office of Dietary Supplements
- Zinc fact sheet, NIH Office of Dietary Supplements
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.