Ferritin-to-Iron Status Calculator

How it is calculated

The tool takes one serum ferritin value in ng/mL (the same number as µg/L) and sorts it into four bands. Below 15 is shown as iron deficiency with depleted stores, 15 up to but not including 30 as low iron stores, 30 up to the upper limit as normal, and above the limit as elevated ferritin, possible overload or inflammation. The upper limit depends on the sex you pick: 200 ng/mL for women and 300 ng/mL for men. Estimated storage iron is ferritin × 8 in mg, a rough rule of about 8 mg per ng/mL. Laboratories use their own reference ranges, so a report from your lab takes precedence over these fixed cut-offs.

Common mistakes

• Entering ferritin in the wrong unit. Results in ng/mL and µg/L are the same number, but a value given in pmol/L is not, so check the unit printed on the report before typing it.
• Leaving the sex at the default male when you are female: the upper limit changes from 200 to 300, so a value between the two is shown as normal rather than elevated.
• Reading a normal band as proof that iron is fine. Ferritin also rises with inflammation, so a value inside the normal range can still hide low iron, and the tool does not know about your other tests.
• Treating the stores figure as a measurement. It is just ferritin times 8, so a result of 22 gives 176 mg and an extreme value such as 5,000 gives an unrealistic mg number.
• Expecting a separate band for children, pregnancy or athletes: the cut-offs are the same fixed values for every adult entry.