What is the conversion factor between g/dL and mmol/L?

Hemoglobin in mmol/L = g/dL × 0.6206. The molar mass of hemoglobin used is approximately 64,500 g/mol (tetramer), giving 1 g/dL ≈ 0.6206 mmol/L.

How does g/dL relate to g/L?

g/L = g/dL × 10. The g/L unit is used in SI-based laboratory systems (common in the UK and many European countries), while g/dL is standard in the US.

What is a normal hemoglobin level?

Normal ranges vary by group. Adult males: 13.5–17.5 g/dL. Adult females: 12.0–15.5 g/dL. Children (general): 11.0–16.0 g/dL. Values below the lower limit suggest anemia; values above the upper limit may indicate polycythemia.

Why is hemoglobin measured in mmol/L in some countries?

Countries using the Système International (SI) report hemoglobin in mmol/L because SI standardizes all concentrations in molar units. The US, UK, Canada, and Australia typically report in g/dL or g/L.

Is mg/dL the same as g/dL for hemoglobin?

No. mg/dL = g/dL × 1000. The mg/dL unit is rarely used for hemoglobin in clinical practice but appears in some older or research contexts. A normal adult male value of 15 g/dL equals 15,000 mg/dL.

Hemoglobin Unit Converter

Name: Hemoglobin Unit Converter
Availability: InStock
Author: Nham Vu

Enter a hemoglobin value in any unit and instantly convert it to g/dL, g/L, mmol/L, and mg/dL with normal-range interpretation.

Enter Hemoglobin Value

Value

Unit

Patient Group

Converted Values

Enter a value above and click Convert.

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Summary

Enter a hemoglobin value in any unit and instantly convert it to g/dL, g/L, mmol/L, and mg/dL with normal-range interpretation.

How it works

Enter your hemoglobin value in the input field.
Select the unit of the value you entered (g/dL, g/L, mmol/L, or mg/dL).
Choose the patient group (adult male, adult female, or children) for reference range comparison.
All four unit equivalents appear instantly below the input.
A status badge shows whether the value is low, normal, or high for the selected group.

Use cases

Convert lab results from SI units (g/L or mmol/L) to the US standard g/dL.
Interpret hemoglobin values from international medical reports.
Quickly check whether a patient's hemoglobin falls within the normal range.
Compare hemoglobin readings from different laboratory systems.
Support clinical decision-making when reviewing blood count results.
Educate patients on what their hemoglobin number means in different units.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu