What is a normal ferritin level?

Laboratory ranges vary, but many print roughly 15 to 150–300 µg/L depending on sex and method. Clinical thresholds for deficiency are separate: below 15 µg/L is clearly depleted, and many clinicians treat below 30 µg/L as iron deficiency.

Is ferritin of 20 too low?

It is inside many labs’ printed ranges but below the 30 µg/L cut-off commonly used for iron deficiency. Whether it matters depends on symptoms and the rest of the panel, so it is worth discussing with your clinician.

Are ng/mL and µg/L the same for ferritin?

Yes. One ng/mL equals one µg/L, so the number is identical in both units.

Can ferritin be normal if I am iron deficient?

Yes, if inflammation or infection is raising it. In that situation guidelines accept higher cut-offs, and clinicians often add CRP and transferrin saturation.

Iron panel · Ferritin

What is a good ferritin level?

Short answer

There are two different numbers people mean. Your lab’s reference range describes what is common in the population it tested. Clinical thresholds describe the level below which iron deficiency is likely. They don’t line up: a ferritin in the 15–30 µg/L range is often printed as “normal” yet sits below the cut-off many clinicians use for deficiency.

Why the printed range can mislead

A reference range is usually the middle 95% of results from a group of people presumed healthy. Iron deficiency is common enough — especially in people who menstruate — that some of those people are themselves low on iron. The bottom of the range is pulled down with them, so a printed lower limit can be well below the level where stores are actually adequate.

Thresholds clinicians commonly use

Ferritin decision points · adults · µg/L (= ng/mL)
Ferritin	What it usually indicates	Where the number comes from
< 15	Iron stores are depleted. Highly specific for deficiency.	WHO 2020 guideline, apparently healthy adults
< 30	Iron deficiency likely — a widely used clinical cut-off, including in people with symptoms.	Common clinical practice; many hematology guidelines
< 45	In people who already have anemia, the AGA recommends <45 ng/mL rather than <15 ng/mL to diagnose iron deficiency. It is not a general target for people without anemia.	AGA 2020 guideline, people with anemia
< 70	May still indicate deficiency when infection or inflammation is present.	WHO 2020 guideline, people with inflammation
Above lab range	Not a sign of “good” iron — see low TIBC for the usual causes.	Read with transferrin saturation

A worked example

A report shows ferritin 22 µg/L with a printed range of 15–150. It carries no “L” flag. But it is below the 30 µg/L threshold, so if the person has symptoms such as tiredness, hair shedding or breathlessness on exertion, many clinicians would consider iron deficiency without anemia. Asking “is 22 low enough to matter for my symptoms?” is a reasonable question to take to an appointment.

Ferritin alone doesn’t settle it. Those symptoms have many causes besides iron, and clinicians read a ferritin result alongside:

Hemoglobin and a complete blood count, including MCV and MCH (red cell size and color)
CRP, to check whether inflammation is propping ferritin up
Transferrin saturation and the rest of the iron panel
Your history: menstrual bleeding, diet, pregnancy, medications and any risk of blood loss

Ferritin units

ng/mL and µg/L are the same number — no conversion is needed. US reports tend to use ng/mL; European reports µg/L.

Why ferritin can look better than it is

Ferritin rises with inflammation, infection, liver disease and heavy alcohol use, independent of iron stores. A “normal” ferritin taken during or soon after an illness can hide a real deficiency, which is why it is often read alongside CRP and transferrin saturation.

Common iron panel patterns · adults, not pregnant
Pattern	Ferritin	Serum iron	TIBC	Saturation	What it usually means
Iron deficiency	↓ low	↓	↑	↓ <20%	Iron stores are used up. The body makes more transferrin to find iron, so TIBC rises.
Early iron depletion	↓ low–borderline	~	~↑	~	Stores are falling but blood iron is still holding up. Hemoglobin is often normal.
Inflammation or chronic illness	~↑	↓	↓	↓	Iron is present but locked away. Low TIBC is what separates this from deficiency.
Deficiency plus inflammation	~ can look normal	↓	~↓	↓ <20%	Inflammation props ferritin up and hides a real shortage. Usually needs CRP to read.
Possible iron overload	↑	↑	↓	↑ >45%	High saturation — not high ferritin alone — is what prompts testing for hemochromatosis.
High ferritin, normal saturation	↑	~	~	~	The most common high-ferritin result. Usually inflammation, liver, alcohol or metabolic — not overload.
Unremarkable	~	~	~	~	Iron status looks adequate. If symptoms continue, iron is unlikely to be the cause.

↑ above range · ↓ below range · ~ within range. Patterns are a starting point for a conversation with your clinician, not a diagnosis.

When to follow up promptly

A low ferritin in a man, or in a woman after menopause, is usually investigated for a source of blood loss. In pregnancy, ferritin targets differ by trimester — ask your midwife or obstetrician rather than using the thresholds above.

Common questions

What is a normal ferritin level?: Laboratory ranges vary, but many print roughly 15 to 150–300 µg/L depending on sex and method. Clinical thresholds for deficiency are separate: below 15 µg/L is clearly depleted, and many clinicians treat below 30 µg/L as iron deficiency.
Is ferritin of 20 too low?: It is inside many labs’ printed ranges but below the 30 µg/L cut-off commonly used for iron deficiency. Whether it matters depends on symptoms and the rest of the panel, so it is worth discussing with your clinician.
Are ng/mL and µg/L the same for ferritin?: Yes. One ng/mL equals one µg/L, so the number is identical in both units.
Can ferritin be normal if I am iron deficient?: Yes, if inflammation or infection is raising it. In that situation guidelines accept higher cut-offs, and clinicians often add CRP and transferrin saturation.