Iron Intake Calculator
iron intake calculator. Get instant, accurate results. Enter values for instant results with step-by-step formulas.
Formula
RDA varies by life stage: Adult male 8 mg, Pre-menopausal female 18 mg, Pregnant 27 mg, Post-menopausal 8 mg | Vegetarians: RDA × 1.8
Iron RDA is based on NIH Dietary Reference Intakes (DRI). The vegetarian multiplier accounts for the lower bioavailability of non-heme iron in plant foods vs heme iron in animal products. The % RDA shows how much of your daily target you're meeting.
Frequently Asked Questions
Why do women of childbearing age need more iron than men?
Menstruating women lose iron monthly through blood loss, requiring an RDA of 18 mg/day compared to 8 mg/day for adult men. During pregnancy, iron needs jump to 27 mg/day to support fetal development, expanded blood volume, and placental tissue. After menopause, iron requirements drop to 8 mg/day — the same as adult males.
What are the symptoms of iron deficiency?
Early iron deficiency may be asymptomatic. As stores deplete, symptoms include: fatigue and weakness, pale skin and gums, shortness of breath on exertion, cold hands and feet, headaches, brittle nails, hair loss, restless leg syndrome, and cravings for ice (pagophagia) or non-food items (pica). A complete blood count (CBC) and serum ferritin test are the most reliable diagnostic tools.
What foods are highest in iron?
Heme iron (most bioavailable): beef (2–3 mg/3oz), lamb, liver (up to 10 mg/3oz), oysters, clams (up to 24 mg/3oz). Non-heme iron: lentils (3.3 mg/½ cup cooked), spinach (3.2 mg/½ cup), tofu (3 mg/½ cup), kidney beans (2 mg/½ cup), pumpkin seeds (4.5 mg/oz), fortified cereals (up to 18 mg/serving).
How do I interpret the result?
Results are displayed with a label and unit to help you understand the output. Many calculators include a short explanation or classification below the result (for example, a BMI category or risk level). Refer to the worked examples section on this page for real-world context.
Can I share or bookmark my calculation?
You can bookmark the calculator page in your browser. Many calculators also display a shareable result summary you can copy. The page URL stays the same so returning to it will bring you back to the same tool.
Is my data stored or sent to a server?
No. All calculations run entirely in your browser using JavaScript. No data you enter is ever transmitted to any server or stored anywhere. Your inputs remain completely private.