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Find which WHO haemoglobin cutoff applies to you by age, sex and pregnancy trimester, apply the published altitude and smoking adjustments, and see which severity band the adjusted value falls in.
This checker tells you which WHO haemoglobin cutoff your report should be read against — 105, 110, 115, 120 or 130 g/L depending on age, sex and pregnancy trimester — then subtracts the published altitude and smoking adjustments from your measured value before comparing it, and shows which severity band the adjusted figure lands in. It is for anyone holding a haemoglobin result who cannot tell whether the printed reference range applies to them, and especially for pregnant readers, because the WHO 2024 guideline sets the second-trimester cutoff at 105 g/L (10.5 g/dL) against 110 g/L in the first and third, while the older WHO/NMH/NHD/MNM/11.1 (2011) table used a single 110 g/L for the whole of pregnancy. Thresholds and adjustment tables are taken from WHO's Guideline on haemoglobin cutoffs to define anaemia in individuals and populations (2024), Tables 2 to 5, with the 2011 figures shown alongside.
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Enter the values you already know.
Fine-tune the options to match your scenario.
Read the result and use it in your planning or reporting.
Separates first (110 g/L), second (105 g/L) and third (110 g/L) trimester instead of using one pregnancy number.
Subtracts the WHO Table 4 elevation figure first, then the Table 5 smoking figure, exactly as the guideline sequences them.
Shows where the current WHO table and the still-widely-quoted 2011 table give a different verdict on the same number.
Places the adjusted value in the WHO mild, moderate or severe band for that specific group.
WHO 2024 sets anaemia at below 110 g/L (11.0 g/dL) in the first trimester, below 105 g/L (10.5 g/dL) in the second, and below 110 g/L (11.0 g/dL) in the third. The second-trimester figure is 5 g/L lower because plasma volume expands faster than red cell mass through mid-pregnancy, diluting haemoglobin. The older WHO 2011 table used a single 110 g/L across all three trimesters, which is why many lab reports and printed charts still disagree with this.
Per WHO 2024 Table 4, subtract 4 g/L at 500–999 m, 8 g/L at 1,000–1,499 m, 11 g/L at 1,500–1,999 m, 14 g/L at 2,000–2,499 m, 18 g/L at 2,500–2,999 m, 21 g/L at 3,000–3,499 m, 25 g/L at 3,500–3,999 m, 29 g/L at 4,000–4,499 m and 33 g/L at 4,500–4,999 m. The subtraction happens before the cutoff is applied, not after. Note the 2024 edition starts adjusting at 500 m; the 2011 edition only started at 1,000 m.
It changes the value you compare, not the cutoff. WHO 2024 Table 5 says subtract 3 g/L for a smoker of fewer than 10 cigarettes a day or of unknown quantity, 5 g/L for 10–19 a day, and 6 g/L for 20 or more. Carbon monoxide binds haemoglobin, so a smoker's measured haemoglobin overstates their oxygen-carrying capacity. If someone both smokes and lives at altitude, both subtractions apply — elevation first, then smoking.
No, and WHO 2024 publishes no conversion factor between them. Venous blood on an automated analyser is the reference method the cutoffs were derived on; capillary readings vary too widely for a fixed correction. A Journal of Global Health 2022 meta-analysis of population surveys found venous readings 3.8 g/L higher than capillary in pre-school children (95% CI 0.8 to 6.7) but no significant difference in non-pregnant women (0.4 g/L, 95% CI −1.9 to 2.8) — the inconsistency itself is the reason no correction exists. A finger-prick screening number and a venous CBC should not be compared directly.
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