What is the normal hemoglobin for women and men?

For non-pregnant women 15+ it’s 120–150 g / L, for men 130–170 g / L. In pregnancy the lower threshold is lower (110 g / L). For children norms depend on age. The calculator compares your value against the range for your group.

What does low hemoglobin mean?

Hemoglobin below the norm is anemia, most often from iron deficiency. Check ferritin, serum iron, vitamin B12 and folate to find the cause. Fatigue, breathlessness and pallor are typical signs, but a doctor makes the diagnosis.

What’s the difference between g / L and g / dL?

They’re the same quantity in different units: g / dL = g / L ÷ 10. For example, 135 g / L is 13.5 g / dL. The calculator accepts both — just pick the units.

Why is normal hemoglobin higher at altitude?

There’s less oxygen at altitude, so the body makes more red cells and hemoglobin — a normal adaptation. WHO recommends accounting for altitude: the calculator adjusts for it if you enter your elevation.

Normal hemoglobin — does that mean my iron is fine?

Not necessarily. Iron stores (ferritin) can be depleted before hemoglobin falls — that’s latent iron deficiency. So if you have fatigue symptoms, check ferritin even when hemoglobin is normal.

Hemoglobin levels in blood

Hemoglobin is the red-blood-cell protein that carries oxygen. Enter your value from a blood test, choose sex and age — the calculator compares it with WHO norms and shows whether it’s normal, low or high. The threshold differs in pregnancy and at high altitude, which you can factor in too.

Check your hemoglobin against the norm

Enter your hemoglobin value — the result appears instantly.

Hemoglobin norms by sex and age

Lower bounds are WHO anemia thresholds; upper bounds are approximate and lab-dependent. Values in grams per litre (g / L).

Group	Norm, g / L
Children 6 mo – 5 y	110–140
Children 5–11 y	115–145
Children 12–14 y	120–150
Men (15+)	130–170
Women (15+)	120–150
Pregnant	110–140

What hemoglobin is and what it shows

Hemoglobin (Hb) is the iron-containing protein of red blood cells that binds oxygen in the lungs and carries it to tissues, taking carbon dioxide back. It’s measured in a complete blood count, usually in grams per litre (g / L); some labs use grams per decilitre (g / dL) — the same number divided by 10.

Hemoglobin depends on sex, age, pregnancy and even the altitude you live at, so there’s no single “normal for everyone” — you compare against the range for your group.

Low hemoglobin: what it means

Hemoglobin below the norm is anemia. The most common cause is iron deficiency (and depleted iron stores — ferritin), along with vitamin B12 and folate deficiency, blood loss and chronic disease. It shows up as fatigue, breathlessness, pallor and brittle hair and nails.

The goal isn’t just to raise the number but to find the cause: hemoglobin is read together with ferritin, serum iron, B12 and other markers. Hemoglobin alone isn’t enough.

High hemoglobin: causes

Hemoglobin above the norm can come from dehydration (the blood is “concentrated”), smoking, living at high altitude, lung and heart disease and, less often, bone-marrow disorders. A persistent rise is a reason to see a doctor — and don’t test while dehydrated.

Altitude and pregnancy adjustment

At altitude the body makes more red cells, so WHO recommends an adjustment: the higher above sea level (from about 1000 m), the higher the value that still counts as normal. The calculator applies this if you enter your altitude.

In pregnancy plasma volume rises faster than red-cell mass, so hemoglobin drops physiologically and the anemia threshold is lower — 110 g / L instead of 120.

Frequently asked questions

For non-pregnant women 15+ it’s 120–150 g / L, for men 130–170 g / L. In pregnancy the lower threshold is lower (110 g / L). For children norms depend on age. The calculator compares your value against the range for your group.
Hemoglobin below the norm is anemia, most often from iron deficiency. Check ferritin, serum iron, vitamin B12 and folate to find the cause. Fatigue, breathlessness and pallor are typical signs, but a doctor makes the diagnosis.
They’re the same quantity in different units: g / dL = g / L ÷ 10. For example, 135 g / L is 13.5 g / dL. The calculator accepts both — just pick the units.
There’s less oxygen at altitude, so the body makes more red cells and hemoglobin — a normal adaptation. WHO recommends accounting for altitude: the calculator adjusts for it if you enter your elevation.
Not necessarily. Iron stores (ferritin) can be depleted before hemoglobin falls — that’s latent iron deficiency. So if you have fatigue symptoms, check ferritin even when hemoglobin is normal.

Hemoglobin is one value from a full blood count

Upload the whole report — AI reads hemoglobin together with ferritin, iron and red cells and explains what’s behind a deviation.

Decode my blood test

This calculator is for reference and information only and is not a diagnosis. A doctor assesses anemia and its causes from the full set of tests.