Daily Iron Calculator
The iron reference changes with sex, age and pregnancy. See the population RDA for the group you select.
Result
Enter the values and press Calculate. Numbers outside the allowed range produce no result.
How is it calculated?
The table lists 18 mg for menstruating women, 8 mg for men and after menopause, and 27 mg in pregnancy. Absorption changes with vitamin C, tea and coffee.
The selected group and age are read from the IOM RDA table
Reference table
| Group | RDA |
|---|---|
| Men 19+ | 8 mg |
| Women 19–50 | 18 mg |
| Women 51+ | 8 mg |
| Pregnancy | 27 mg |
How should you read the result?
Low ferritin is not detected here. Do not start a supplement without a clinician; excess iron can be harmful.
Frequently asked questions
How much iron do women need?
The RDA is 18 mg from 19 to 50. It falls to 8 mg after menopause.
Why does pregnancy raise iron?
Blood volume and the baby raise the need. The table shows 27 mg; a personal dose depends on blood counts.
Which foods contain iron?
Red meat, offal, lentils, molasses and dark leafy greens. Vitamin C raises absorption of plant iron.
Does tea block iron?
Tea and coffee with a meal can lower plant-iron absorption. Drinking them apart from the meal makes a difference.