Iron Intake Calculator Formula

Understand the math behind the iron intake calculator. Each variable explained with a worked example.

Use the Iron Intake Calculator

Formulas Used

Recommended Iron

daily_iron = base_iron * is_vegetarian

Upper Limit

upper_limit = age <= 13 ? 40 : 45

Variables

VariableDescriptionDefault
ageAge(years)30
is_vegetarianDietary Pattern1
base_ironDerived value= age <= 3 ? 7 : (age <= 8 ? 10 : (age <= 13 ? 8 : (age <= 18 ? 11 : 8)))calculated

How It Works

Iron Intake Recommendations

Iron is essential for oxygen transport in the blood. Requirements vary by age and dietary pattern.

RDA for Males

| Age | RDA | |---|---| | 1-3 years | 7 mg | | 4-8 years | 10 mg | | 9-13 years | 8 mg | | 14-18 years | 11 mg | | 19+ years | 8 mg |

Vegetarians need 1.8x more iron because plant-based (non-heme) iron is less readily absorbed.

Worked Example

A 30-year-old omnivore.

age = 30is_vegetarian = 1
  1. 01Age 19+ base iron = 8 mg
  2. 02Omnivore multiplier = 1.0
  3. 03Daily iron = 8 x 1.0 = 8.0 mg
  4. 04Upper limit (adult) = 45 mg

Ready to run the numbers?

Open Iron Intake Calculator