Health

Daily Iron Requirements by Sex & Age

Calculator Free · Private
Was this calculator helpful?

Daily iron requirements are based on population studies (NHANES, WHO) and reviewed regularly to keep you current. These reference values provide a framework for understanding your results, but your personal health context always takes priority. Men need 8mg, women need 18mg, and pregnant women need 27mg of iron per day. Values are current as of 2026 and reviewed periodically.

Last reviewed: May 12, 2026 Verified by Hacé Cuentas Team Source: NIST — National Institute of Standards and Technology, Khan Academy, Wolfram MathWorld 100% private

When to use this calculator

  • Technical calculations related to daily iron requirements by sex and age
  • Students and healthcare professionals
  • Validate theoretical results before applying them
  • Teaching and learning the concept
  • Quick reference in healthcare projects

Calculation Example

  1. Typical values
  2. Result
Result: Result

How it works

1 min read

Normal health reference values come from large population studies (NHANES, WHO, CDC). They vary by age, sex, ethnicity, and region. These are guidelines; your personal medical history always takes priority.

How It's Calculated

Men: 8mg, Women: 18mg, Pregnant women: 27mg per day.

This calculator applies the formula with your entered values, checking typical ranges and alerting you to values outside normal recommendations.

Normal Reference Values

ParameterNormal Adult Range
Blood Pressure<120/80 mmHg
Resting Heart Rate60-100 bpm
Body Temperature36.1-37.2°C
Oxygen Saturation (SpO2)95-100%
Fasting Blood Glucose70-100 mg/dL
HbA1c<5.7%
Total Cholesterol<200 mg/dL
LDL Cholesterol<100 mg/dL
HDL Cholesterol>40 (Men) / >50 (Women)

Final Notes

This calculation is a reference guide only. For critical decisions (financial, medical, legal), consult a qualified healthcare professional. Values are current as of 2026 and reviewed periodically.

Frequently asked questions

How much iron do I need daily?

Adult men need 8mg per day, adult women need 18mg per day, and pregnant women need 27mg per day according to WHO guidelines.

Why do women need more iron than men?

Women of reproductive age require more iron due to menstrual blood loss. Iron needs decrease after menopause.

How much iron do pregnant women need?

Pregnant women need 27mg of iron daily to support fetal development and increased blood volume during pregnancy.

What are signs of iron deficiency?

Symptoms include fatigue, weakness, shortness of breath, dizziness, pale skin, headaches, and difficulty concentrating.

What are good sources of dietary iron?

Red meat, poultry, fish, legumes, fortified cereals, dark leafy greens, and nuts are excellent sources. Pairing with vitamin C increases absorption.

Is this calculator accurate for medical diagnosis?

This is a reference guide only. For medical diagnosis or treatment decisions, consult a healthcare professional and get a blood test.

Can you take too much iron?

Yes. Excess iron can damage organs over time. Never exceed recommended amounts without medical supervision, and always take supplements as directed by a doctor.

How is iron deficiency diagnosed?

Through blood tests measuring serum iron, ferritin, and hemoglobin levels. Your doctor will interpret results in your specific health context.

Do medications affect iron absorption?

Yes. Many medications including antacids and certain antibiotics can interfere with iron absorption. Inform your healthcare provider about all medications you take.

Sources and references