How to Convert Serum Iron µg/dL to µmol/L
Serum iron measures the amount of iron bound to transferrin in your blood. US labs usually report it in µg/dL, while most other countries use µmol/L. Converting lets you compare a result with reference ranges from either system.
The conversion factor is 0.179, derived from iron's atomic weight of 55.85 g/mol:
Serum iron µmol/L = Serum iron µg/dL × 0.179 Serum iron µg/dL = Serum iron µmol/L ÷ 0.179 Serum Iron µg/dL to µmol/L Chart
Use this chart to compare common serum iron values. Reference ranges vary by laboratory, sex, and time of day, so always check the range printed on your own report.
| µg/dL | µmol/L | Typical context |
|---|---|---|
| 30 µg/dL | 5.4 µmol/L | Low |
| 50 µg/dL | 9.0 µmol/L | Low–normal |
| 60 µg/dL | 10.7 µmol/L | Lower limit of many ranges |
| 100 µg/dL | 17.9 µmol/L | Mid-normal |
| 150 µg/dL | 26.9 µmol/L | Upper-normal |
| 170 µg/dL | 30.4 µmol/L | Upper limit of many ranges |
| 200 µg/dL | 35.8 µmol/L | Elevated |
| 300 µg/dL | 53.7 µmol/L | High / possible overload |
µmol/L to µg/dL Reverse Chart
| µmol/L | µg/dL |
|---|---|
| 5 µmol/L | 27.9 µg/dL |
| 10 µmol/L | 55.9 µg/dL |
| 15 µmol/L | 83.8 µg/dL |
| 20 µmol/L | 111.7 µg/dL |
| 25 µmol/L | 139.7 µg/dL |
| 30 µmol/L | 167.6 µg/dL |
Normal Serum Iron Reference Ranges
Reference ranges differ by laboratory and by sex. Commonly cited adult values are:
| Group | Conventional (µg/dL) | SI (µmol/L) |
|---|---|---|
| Adult men | 65–176 µg/dL | 11.6–31.5 µmol/L |
| Adult women | 50–170 µg/dL | 9.0–30.4 µmol/L |
| General adult (often cited) | 60–170 µg/dL | 10.7–30.4 µmol/L |
Serum iron is rarely interpreted alone. It is read together with TIBC and transferrin saturation, and with ferritin, which reflects iron stores. Low iron with low ferritin supports iron deficiency; high iron with high transferrin saturation supports iron overload.
Worked Example
Suppose your serum iron is 45 µg/dL and you want µmol/L:
45 × 0.179 = 8.1 µmol/L 8.1 µmol/L is below the usual lower limit, which would typically prompt a look at transferrin saturation and ferritin. For the reverse direction, 20 µmol/L is about 112 µg/dL.
Frequently Asked Questions
How do you convert serum iron µg/dL to µmol/L?
Multiply µg/dL by 0.179. For example, 100 µg/dL equals about 17.9 µmol/L.
How do you convert serum iron µmol/L to µg/dL?
Divide µmol/L by 0.179 (or multiply by 5.587). For example, 20 µmol/L is about 112 µg/dL.
What is a normal serum iron level?
Roughly 60–170 µg/dL (about 10.7–30.4 µmol/L) for adults, with men slightly higher than women. Ranges vary by lab and time of day.
Is serum iron the same as ferritin?
No. Serum iron is the iron circulating in blood right now; ferritin reflects stored iron. They are different tests with different units and are interpreted together.
References
- Merck Manual Professional Edition — Iron Deficiency Anemia (serum iron, TIBC, and reference values).
- Iron atomic weight 55.85 g/mol — SI conversion factor 1 µg/dL = 0.179 µmol/L (standard clinical laboratory unit conversion).
Conclusion
Converting serum iron between µg/dL and µmol/L is a simple multiply or divide by 0.179. Use this calculator to compare results across labs, then interpret iron alongside TIBC, transferrin saturation, and ferritin with your healthcare provider.