This free iron intake calculator answers how much iron you need a day, showing the recommended daily amount and safe upper limit by age and sex — general reference information, not a treatment dose for deficiency.
Values follow widely used reference intakes (IOM/NIH) for healthy people. Vegetarians may need more, as plant iron is less easily absorbed.
General guidance for healthy people. Good food sources include red meat, beans, lentils, tofu, fortified cereals and leafy greens. Pair plant iron with vitamin C to absorb more. For deficiency, see a doctor.
How the Iron Intake Calculator Works
This tool shows the general recommended daily iron intake (RDA) and the safe upper limit (UL) for a given age or life stage, based on widely used reference tables for healthy people. It is a reference lookup, not a personalized dose for treating iron deficiency or anemia.
Formula: RDA (mg/day) = reference value for your selected Age / life stage group, using the female column when Female is selected (except the Pregnant and Breastfeeding groups, which use one fixed value regardless of the sex toggle). Safe Upper Limit (mg/day) is a separate fixed ceiling for that same age/life-stage group and does not change with sex.
- Age / life stage — the bracket you select: infant (7-12 months), child (1-3, 4-8, or 9-13 years), teen (14-18 years), adult (19-50 or 51+ years), pregnant, or breastfeeding.
- Sex — male or female, used to pick the correct RDA value for teen and adult groups (this field is hidden for the pregnant and breastfeeding groups, which use one shared value).
Example Scenarios
| Age / Life Stage | Sex | Recommended Intake (mg/day) |
|---|---|---|
| Infant (7-12 months) | N/A | 11 mg |
| Child (4-8 years) | N/A | 10 mg |
| Teen (14-18 years) | Male | 11 mg |
| Teen (14-18 years) | Female | 15 mg |
| Adult (19-50 years) | Female | 18 mg |
| Pregnant | — | 27 mg |
Getting More from the Iron Intake Calculator Figures
The iron intake calculator shows a daily target, but how much iron you absorb depends heavily on what you eat it with.
- Haem iron from meat, poultry and fish is absorbed much better than non-haem iron from beans, lentils, tofu, fortified cereals and leafy greens.
- Vitamin C boosts absorption of plant iron, so pair those foods with fruit, peppers or tomatoes.
- Tea, coffee and calcium can reduce absorption; have them between meals rather than with iron-rich food.
Because plant iron is absorbed less well, vegetarians and vegans need more total iron, which is worth remembering when reading the iron intake calculator result.
Do not take iron supplements just to reach the iron intake calculator figure without advice. Too much iron causes stomach upset and can build up to harmful levels, and iron tablets are dangerous to young children, so keep them out of reach. Tiredness has many causes; a blood test confirms deficiency, and a doctor should decide any treatment dose rather than the iron intake calculator. The NIH Office of Dietary Supplements iron fact sheet gives the evidence behind each iron intake calculator value.
Iron Intake Calculator FAQ
What’s the difference between the recommended intake and the safe upper limit?
The recommended intake (RDA) is the general daily amount healthy people are advised to get, mainly from food. The upper limit (UL) is a much higher ceiling that shouldn’t be exceeded from supplements without medical advice, since iron overdose can be dangerous.Why do women need more iron than men in some age groups?
Menstruating women lose iron monthly through blood loss, so the recommended intake for adult women (19-50) is notably higher — about 18 mg/day versus 8 mg/day for men in the same age range — to help replace what’s lost.How much more iron do I need during pregnancy?
Iron needs rise sharply in pregnancy, to around 27 mg/day, to support increased blood volume and the baby’s development. Many people are advised to take a supplement, but this should be on a doctor’s or midwife’s recommendation rather than a default choice.Can I take too much iron, and who needs to be extra careful?
Yes — iron supplementation should be guided by a doctor and, ideally, a blood test. This is especially important for anyone with hemochromatosis or other iron-overload conditions, and iron supplements can be very dangerous in overdose, particularly for children.What’s the best way to reach my recommended iron intake?
Aim to meet the recommended amount mainly through food such as red meat, beans, lentils, tofu, fortified cereals and leafy greens. Pairing plant-based (non-heme) iron with vitamin C can help your body absorb more of it.Does this calculator diagnose iron deficiency or anemia?
No. This tool only shows general reference intake levels for healthy people by age and life stage. It cannot diagnose deficiency or anemia — that requires a blood test and a doctor’s evaluation.Related Calculators
If you’re checking your iron levels, it can also help to look at your broader diet and risk factors with the anemia risk calculator, compare it against your daily magnesium dosage needs, or check whether you’re meeting your recommended vitamin D intake at the same time.