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Check iron intake vs RDA by age and sex — see mg/day, % of RDA and heme vs non-heme tips.
Check iron intake vs RDA by age and sex — see mg/day, % of RDA and heme vs non-heme tips.
Enter values above and click Calculate — results will appear here with the formula explained.
Iron needs follow Recommended Dietary Allowances that differ by sex, age and absorption factor: adult men typically need about 8 mg daily, adult women about 18 mg during fertile years due to menstrual losses, rising to 27 mg during pregnancy. Heme iron from meat absorbs at 15–35% efficiency, while non-heme from plants manages only 2–20%, a gap vitamin C co-ingestion can narrow by enhancing absorption — the calculator weights those sources separately and reports percentage of the age/sex RDA so the figure is contextual, not absolute milligrams alone.
Supplementation above dietary intake warrants testing; iron overload is harmful and self-prescribing high doses without ferritin guidance risks harm. Pair iron-rich meals with citrus, avoid tea or coffee at the same sitting which inhibits uptake, and confirm any persistent fatigue-driven dosing with laboratory work rather than the calculator alone.
Check iron intake vs RDA by age and sex — see mg/day, % of RDA and heme vs non-heme tips. Formula: RDA: M 8mg (19+), F 18mg (19-50), 8mg (51+), 27mg pregnancy.
Iron needs follow Recommended Dietary Allowances that differ by sex, age and absorption factor: adult men typically need about 8 mg daily, adult women about 18 mg during fertile years due to menstrual losses, rising to 27 mg during pregnancy. Heme iron from meat absorbs at 15–35% efficiency, while non-heme from plants manages only 2–20%, a gap vitamin C co-ingestion can narrow by enhancing absorption — the calculator weights those sources separately and reports percentage of the age/sex RDA so the figure is contextual, not absolute milligrams alone.
Supplementation above dietary intake warrants testing; iron overload is harmful and self-prescribing high doses without ferritin guidance risks harm. Pair iron-rich meals with citrus, avoid tea or coffee at the same sitting which inhibits uptake, and confirm any persistent fatigue-driven dosing with laboratory work rather than the calculator alone.
At 30, female, intake 12mg: RDA 18mg, so 66.7% — increase lean meat, beans or fortified cereals.
Formulas are standard public references (see our methodology). External standards are cited in the text where they apply.
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