Iron Intake Calculator
Daily iron target by age, sex and diet type.
Enter your values
Choose one of: Adult male, Menstruating female, Pregnant, Post-menopausal, Teen male.
Choose one of: Includes meat, Vegetarian / vegan.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Daily iron target
- 18 mg
- Base RDA
- 18 mg
- Diet adjustment
- 1x
- Upper limit
- 45 mg/day for adults
Quick answer
Iron needs vary widely: 8 mg for adult men, 18 mg for menstruating women, and up to 1.8x more on a plant-based diet.
target = base RDA x diet factor
At a glance
| What it does | Daily iron target by age, sex and diet type. |
|---|---|
| Category | Health |
| Inputs needed | Group, Diet |
| Main output | Daily iron target |
| Formula | target = base RDA x diet factor |
| Cost | Free — no sign-up, no download |
How to use the Iron Intake Calculator
- 1Pick the group that matches your age and life stage.
- 2Select your diet type — plant iron is absorbed far less efficiently.
- 3Pair iron-rich foods with vitamin C to boost absorption.
Inputs explained
- Group
- Choose one of: Adult male, Menstruating female, Pregnant, Post-menopausal, Teen male.
- Diet
- Choose one of: Includes meat, Vegetarian / vegan.
Worked example
Using the values the calculator loads with:
Inputs
- GroupMenstruating female
- DietIncludes meat
Results
- Daily iron target18 mg
- Base RDA18 mg
- Diet adjustment1x
- Upper limit45 mg/day for adults
Frequently asked questions
Why do vegetarians need more?
Non-haem iron from plants is absorbed at roughly half the rate of haem iron from meat.
Should I supplement?
Only after a blood test — excess iron accumulates and is harmful.
What do I need to enter into the Iron Intake Calculator?
Just 2 values: group, diet. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Iron Intake Calculator work out the answer?
Iron needs vary widely: 8 mg for adult men, 18 mg for menstruating women, and up to 1.8x more on a plant-based diet. It applies the formula target = base RDA x diet factor and shows the working so you can check each step by hand.
Is the Iron Intake Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.