Anaemia Severity Classifier (WHO 2024)

Q: What changed in the WHO 2024 anaemia cutoffs?

Two things. Children aged 6 to 23 months came down from 110 to 105 g/L, splitting off from the old single 6-to-59-month band, and pregnancy gained a separate second-trimester cutoff of 105 g/L where 2011 used 110 g/L throughout pregnancy. Everything else is unchanged: 115 g/L for children 5 to 11, 120 for 12 to 14 and for non-pregnant women 15 to 65, 130 for men 15 to 65, 110 for the first and third trimesters, and the same mild, moderate and severe boundaries as before.

Q: Are the WHO anaemia cutoffs in g/L or g/dL?

g/L. The WHO tables are printed in grams per litre, so the adult male cutoff is 130 g/L, which is 13.0 g/dL, and the cutoff for children of 6 to 23 months is 105 g/L, which is 10.5 g/dL. A table circulating with these numbers labelled g/dL is wrong by a factor of ten in every cell — a haemoglobin of 105 g/dL is not possible. Divide the g/L figure by ten for g/dL, or multiply a g/dL result by ten before using this page.

Q: What haemoglobin counts as severe anaemia?

Below 70 g/L (7.0 g/dL) in children under 5 and in pregnancy, and below 80 g/L (8.0 g/dL) from 5 years upward, including all adults. The severe boundary does not scale with the group's anaemia cutoff, so the same 75 g/L is severe in a pregnant woman and moderate in a man. These boundaries were not re-derived in 2024: the guideline records that no change to the severity methodology was recommended because the evidence was insufficient.

Q: How do you adjust haemoglobin for altitude and smoking?

Subtract the published adjustment from the measured haemoglobin, or equivalently add it to the cutoff. For elevation, WHO 2024 gives 0 g/L below 500 m, then 4, 8, 11, 14, 18, 21, 25, 29 and 33 g/L in 500 m steps up to 5,000 m. For smoking, 3 g/L for a smoker whose consumption is unknown or under 10 a day, 5 g/L for 10 to 19 a day and 6 g/L for more than 20. The altitude figures are large — 21 g/L at 3,000 m is wider than the whole mild band for a woman — so they change classifications rather than nudging them.

Q: Is a haemoglobin above the WHO cutoff normal?

Not necessarily. The cutoff is the fifth percentile of a healthy reference distribution, so it was built to place one healthy person in twenty below it, and it says nothing about a person whose own haemoglobin has fallen substantially while staying inside the population interval. Iron deficiency without anaemia is common and is not excluded by a normal haemoglobin — that needs a ferritin. And the red cell indices can be clearly abnormal with a normal haemoglobin, which is how thalassaemia trait is usually found.

Q: Why is the men's cutoff 130 g/L and not 135?

Because the guideline development group chose to leave it. The 2024 guideline states that the data in adult men may suggest a higher cutoff of 135 g/L, but that it retained 130 g/L after considering the uncertainty in the evidence, the implications of iron therapy for men, and the potential unintended consequences. It is a deliberate policy judgement about population programmes, recorded in the guideline, and it is the plainest illustration that these cutoffs are epidemiological thresholds rather than clinical action points.

Q: Can a finger-prick haemoglobin be used with these cutoffs?

The guideline recommends venous blood on an automated haematology analyser with high-quality control measures. On capillary sampling it says there is clear variation between capillary and venous haemoglobin but that the magnitude has not been confirmed, so it is not possible to provide an adjustment that makes the two comparable. A capillary result that falls near a cutoff should be repeated on a venous sample rather than corrected.

Grade a haemoglobin against the revised WHO 2024 cutoffs — in g/L and g/dL, with the altitude and smoking adjustments applied, and with the 2011 values beside them so you can see that exactly two things changed.

Last updated 17 Sep 2026

WHO 2024 anaemia cutoffs and severity bands

Group + haemoglobin → WHO severity

Population groupThese are the exact groups the WHO 2024 table publishes, and no others. The guideline gives one cutoff for children aged 12 to 14 and one for non-pregnant women aged 15 to 65, and they are the same figure, which is why they share an option here. The table stops at 65: WHO publishes no separate cutoff above that age, and the record does not invent one. Boys and girls aged 12 to 14 carry the same cutoff in the 2024 table.

Haemoglobin (g/L)Grams per LITRE, which is the unit the WHO tables are printed in. Multiply a g/dL result by ten: 10.5 g/dL is 105 g/L, and 13.0 g/dL is 130 g/L. This is the single commonest error on this subject — a table copied out of the guideline with the units changed to g/dL is wrong by a factor of ten in every cell, and a haemoglobin of 105 g/dL is not a low result but an impossible one. Every verdict on this page prints both units so the mistake is visible if it has been made.

Elevation of residenceHaemoglobin rises with altitude, so an unadjusted value overstates oxygen-carrying adequacy in someone living high up. The figures are WHO 2024's Table 4, in 500 m increments, and the guideline applies them by subtracting from the measured haemoglobin or adding to the cutoff — this page subtracts. The elevation that matters is where the person lives, not where the blood was taken, and a recent arrival at altitude has not yet made the extra haemoglobin the adjustment assumes.

SmokingCarbon monoxide from smoking raises haemoglobin without raising oxygen delivery, so the same arithmetic applies. WHO 2024's Table 5 gives 3 g/L both for a smoker whose consumption is unknown and for fewer than 10 cigarettes a day, 5 g/L for 10 to 19 and 6 g/L for more than 20, which is why the first two share an option here. The guideline's supporting figure is a mean haemoglobin 3.3 g/L higher in smokers than non-smokers across all surveys. No adjustment is published for other tobacco products or for second-hand exposure, and this page does not extrapolate one.

Moderate anaemia — 80 to 109 g/L (8.0 to 10.9 g/dL)Example

Non-pregnant woman aged 34, haemoglobin 98 g/L, lives at sea level, non-smoker

WHO 2024 cutoffs and severity bands, in both units

The first figure in each cell is the guideline's own, in g/L; the second is the same number in g/dL, divided by ten. The WHO tables are printed in g/L, and a version of this table circulating in g/dL is wrong by a factor of ten in every cell. Read across rather than down: the severe boundary is 70 or 80 g/L regardless of how high the group's cutoff is, so the width of the moderate band varies from 25 g/L in a young child to 30 in an adult, and the mild band from 5 g/L in a 5-to-11-year-old to 20 in a man.
Group	Anaemia below	Mild	Moderate	Severe
Children 6 to 23 months	105 g/L · 10.5 g/dL	95–104 · 9.5–10.4	70–94 · 7.0–9.4	<70 · <7.0
Children 24 to 59 months	110 g/L · 11.0 g/dL	100–109 · 10.0–10.9	70–99 · 7.0–9.9	<70 · <7.0
Children 5 to 11 years	115 g/L · 11.5 g/dL	110–114 · 11.0–11.4	80–109 · 8.0–10.9	<80 · <8.0
Children 12 to 14 years	120 g/L · 12.0 g/dL	110–119 · 11.0–11.9	80–109 · 8.0–10.9	<80 · <8.0
Non-pregnant women 15 to 65	120 g/L · 12.0 g/dL	110–119 · 11.0–11.9	80–109 · 8.0–10.9	<80 · <8.0
Men 15 to 65	130 g/L · 13.0 g/dL	110–129 · 11.0–12.9	80–109 · 8.0–10.9	<80 · <8.0
Pregnancy, first trimester	110 g/L · 11.0 g/dL	100–109 · 10.0–10.9	70–99 · 7.0–9.9	<70 · <7.0
Pregnancy, second trimester	105 g/L · 10.5 g/dL	95–104 · 9.5–10.4	70–94 · 7.0–9.4	<70 · <7.0
Pregnancy, third trimester	110 g/L · 11.0 g/dL	100–109 · 10.0–10.9	70–99 · 7.0–9.9	<70 · <7.0

2024 against 2011: exactly two cells moved

This comparison is the reason to read this page rather than a page carrying one table. The 2024 guideline changed two things and left everything else standing: children of 6 to 23 months came down from 110 to 105 g/L, and the second trimester of pregnancy got its own cutoff of 105 g/L where 2011 had a single figure of 110 for the whole of pregnancy. The 2011 column is built from what the 2024 guideline and its published summary state about the values they replaced, and from the WHO nutrition information system's own wording of the 2011 figures; the underlying 2011 report itself was not retrievable during authoring, so treat it as sourced at one remove.
Group	WHO 2011	WHO 2024	Changed?
Children 6 to 23 months	110 g/L (within a single 6–59 month band)	105 g/L	Yes — lowered by 5 g/L
Children 24 to 59 months	110 g/L (same single band)	110 g/L	No — the band split, the number did not
Children 5 to 11 years	115 g/L	115 g/L	No
Children 12 to 14 years	120 g/L	120 g/L	No
Non-pregnant women 15 to 65	120 g/L	120 g/L	No
Men 15 to 65	130 g/L	130 g/L	No
Pregnancy, first trimester	110 g/L (one cutoff for all of pregnancy)	110 g/L	No
Pregnancy, second trimester	110 g/L (same single cutoff)	105 g/L	Yes — a new, separate, lower cutoff
Pregnancy, third trimester	110 g/L (same single cutoff)	110 g/L	No
Mild / moderate / severe boundaries	70 or 80 g/L by group	70 or 80 g/L by group	No — severity methodology was left alone

The adjustments, and how to apply them

Both tables are WHO 2024's own (Tables 4 and 5), and the guideline applies them by subtracting the value from the measured haemoglobin or, equivalently, adding it to the cutoff. The scale matters: at 3,000 m the adjustment is 21 g/L, which is larger than the entire mild band for a woman and would move a great many people from 'not anaemic' into 'mild'. Both are population corrections used on individuals — the altitude figure assumes acclimatisation has happened, and the smoking figure assumes a steady state — so they are a better answer than ignoring the problem and a worse one than knowing the person's own baseline.
Elevation of residence	Subtract	Smoking	Subtract
1 to 499 m	0 g/L	Non-smoker	0 g/L
500 to 999 m	4 g/L	Smoker, amount unknown	3 g/L
1000 to 1499 m	8 g/L	Fewer than 10 cigarettes a day	3 g/L
1500 to 1999 m	11 g/L	10 to 19 cigarettes a day	5 g/L
2000 to 2499 m	14 g/L	More than 20 cigarettes a day	6 g/L
2500 to 2999 m	18 g/L	—	—
3000 to 3499 m	21 g/L	Mean difference, smokers vs non-smokers	3.3 g/L (95% CI 2.5–4.0)
3500 to 3999 m	25 g/L	Other tobacco, second-hand exposure	No published adjustment
4000 to 4499 m	29 g/L	—	—
4500 to 4999 m	33 g/L	—	—

Two numbers changed, the unit is g/L, and a cutoff is not a treatment threshold

The WHO revised its haemoglobin cutoffs for anaemia in 2024, and most of what is written about them online still carries the 2011 figures. The revision is narrower than the word 'revised' suggests. Two cells moved. Children aged 6 to 23 months came down from 110 to 105 g/L, splitting off from what had been a single 6-to-59-month band. And pregnancy, which had one cutoff of 110 g/L for all three trimesters, gained a separate second-trimester cutoff of 105 g/L. Everything else — 115 g/L at 5 to 11 years, 120 for 12 to 14 and for non-pregnant women, 130 for men, and the mild, moderate and severe boundaries in every group — is what it was. A reader who knows that can update their practice in two sentences instead of relearning a table.

The unit is grams per litre. This sounds like pedantry and is not: a version of the WHO table with the unit changed to g/dL is wrong by a factor of ten in every cell, and 105 g/dL is not a low haemoglobin but an impossible one. Because g/dL is the form printed on most reports in the UK, Ireland and North America, the conversion has to happen somewhere, and doing it once in the head is where it goes wrong. Every verdict and every table on this page gives both units, derived from the g/L figure, so a tenfold error is visible rather than silent.

What the cutoffs are is a statistical construct, and the guideline is unusually candid about it. They come from an analysis that calculated the fifth percentiles of haemoglobin distributions in apparently healthy, ethnically diverse populations, and, as the guideline puts it, the fifth percentile implies that 95% of healthy individuals have a higher value and 5% of healthy individuals still have a lower one. One healthy person in twenty is therefore below the cutoff by design. The corollary is more useful: a fall of 25 g/L from a person's own previous result is abnormal for that person whether or not it crosses the line, and a previous full blood count beats this classification every time.

The men's cutoff shows what kind of number this is. The guideline records that the data "may suggest a higher haemoglobin cutoff (i.e. 135 g/L)" for adult men but that the development group retained 130 g/L after weighing the uncertainty in the evidence, the implications of iron therapy for men, and the potential unintended consequences. That is a policy decision about programmes, made explicitly, and it is the clearest available evidence that these are epidemiological thresholds rather than treatment triggers. The guideline says as much about management: it "could vary depending on the clinical scenario and the underlying cause(s) of the anaemia". Nothing on this page decides whether to transfuse, prescribe iron or investigate.

Two practical caveats sit underneath all of it. The first is the sample: the guideline recommends venous blood on an automated analyser with proper quality control, and states that the variation between capillary and venous haemoglobin is real but its magnitude unconfirmed, so no correction between them can be offered. A finger-prick result and a venous result are not interchangeable and cannot be made so. The second is that a grade is not a diagnosis. Classifying the anaemia is the separate and more useful question, and the answers are on the same report — the mean cell volume, the red cell distribution width, the reticulocyte count and ferritin. The MCV-based type classifier takes that next step, and the haemoglobin unit converter handles g/dL, g/L and the mmol/L form used in the Netherlands and Scandinavia.

Frequently asked questions

What changed in the WHO 2024 anaemia cutoffs?

Two things. Children aged 6 to 23 months came down from 110 to 105 g/L, splitting off from the old single 6-to-59-month band, and pregnancy gained a separate second-trimester cutoff of 105 g/L where 2011 used 110 g/L throughout pregnancy. Everything else is unchanged: 115 g/L for children 5 to 11, 120 for 12 to 14 and for non-pregnant women 15 to 65, 130 for men 15 to 65, 110 for the first and third trimesters, and the same mild, moderate and severe boundaries as before.

Are the WHO anaemia cutoffs in g/L or g/dL?

g/L. The WHO tables are printed in grams per litre, so the adult male cutoff is 130 g/L, which is 13.0 g/dL, and the cutoff for children of 6 to 23 months is 105 g/L, which is 10.5 g/dL. A table circulating with these numbers labelled g/dL is wrong by a factor of ten in every cell — a haemoglobin of 105 g/dL is not possible. Divide the g/L figure by ten for g/dL, or multiply a g/dL result by ten before using this page.

What haemoglobin counts as severe anaemia?

Below 70 g/L (7.0 g/dL) in children under 5 and in pregnancy, and below 80 g/L (8.0 g/dL) from 5 years upward, including all adults. The severe boundary does not scale with the group's anaemia cutoff, so the same 75 g/L is severe in a pregnant woman and moderate in a man. These boundaries were not re-derived in 2024: the guideline records that no change to the severity methodology was recommended because the evidence was insufficient.

How do you adjust haemoglobin for altitude and smoking?

Subtract the published adjustment from the measured haemoglobin, or equivalently add it to the cutoff. For elevation, WHO 2024 gives 0 g/L below 500 m, then 4, 8, 11, 14, 18, 21, 25, 29 and 33 g/L in 500 m steps up to 5,000 m. For smoking, 3 g/L for a smoker whose consumption is unknown or under 10 a day, 5 g/L for 10 to 19 a day and 6 g/L for more than 20. The altitude figures are large — 21 g/L at 3,000 m is wider than the whole mild band for a woman — so they change classifications rather than nudging them.

Is a haemoglobin above the WHO cutoff normal?

Not necessarily. The cutoff is the fifth percentile of a healthy reference distribution, so it was built to place one healthy person in twenty below it, and it says nothing about a person whose own haemoglobin has fallen substantially while staying inside the population interval. Iron deficiency without anaemia is common and is not excluded by a normal haemoglobin — that needs a ferritin. And the red cell indices can be clearly abnormal with a normal haemoglobin, which is how thalassaemia trait is usually found.

Why is the men's cutoff 130 g/L and not 135?

Because the guideline development group chose to leave it. The 2024 guideline states that the data in adult men may suggest a higher cutoff of 135 g/L, but that it retained 130 g/L after considering the uncertainty in the evidence, the implications of iron therapy for men, and the potential unintended consequences. It is a deliberate policy judgement about population programmes, recorded in the guideline, and it is the plainest illustration that these cutoffs are epidemiological thresholds rather than clinical action points.

Can a finger-prick haemoglobin be used with these cutoffs?

The guideline recommends venous blood on an automated haematology analyser with high-quality control measures. On capillary sampling it says there is clear variation between capillary and venous haemoglobin but that the magnitude has not been confirmed, so it is not possible to provide an adjustment that makes the two comparable. A capillary result that falls near a cutoff should be repeated on a venous sample rather than corrected.

Related calculators

References

World Health Organization. Guideline on Haemoglobin Cutoffs to Define Anaemia in Individuals and Populations. Geneva: WHO; 2024 (ISBN 9789240088542) — the cutoff and severity tables in g/L, the 500 m elevation adjustments, the smoking adjustments, the 5th-percentile derivation, the 135 g/L discussion for men, the capillary-versus-venous statement, and the decision not to revise the severity methodology.
Revised WHO guidelines on haemoglobin cutoffs to define anaemia in individuals and populations. Indian Pediatr. 2024;61:671 — an independent reproduction of the full 2024 cutoff and severity table and of the elevation adjustment table, used here to confirm every figure a second time.
World Health Organization. Haemoglobin Concentrations for the Diagnosis of Anaemia and Assessment of Severity. Vitamin and Mineral Nutrition Information System. WHO/NMH/NHD/MNM/11.1; 2011 — the superseded cutoffs, including the single 6-to-59-month band at 110 g/L and the single pregnancy cutoff of 110 g/L.
World Health Organization. Nutrition Landscape Information System: anaemia — the 2011 figures quoted in WHO's own words, defining anaemia in children under 5 and in pregnancy as haemoglobin below 110 g/L at sea level and in non-pregnant women as below 120 g/L.

Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.