# Lab unit converter (conventional and SI units)

> Doctano turns the lab reports you already have into one private, source-linked health timeline, with an AI that answers from your own results.

Change the scale without changing the result, and see why the number moves when the unit does.

This is the Markdown version of https://doctano.com/tools/unit-converter. The HTML page is the canonical version and carries the interactive converter.

This converter changes common lab values between conventional units such as mg/dL and SI units such as mmol/L. It uses the conversion factors listed below. A conversion changes the scale, not the measurement, and it does not tell you whether a value is normal or replace the units and range on your report.

## What this converter does

Every lab result has a value, a unit, and a reference range. When two reports use different units, the values look different even when the measurement is the same. This converter changes the scale so the numbers can be compared. It does not change the underlying result, and it does not choose a range.

The factors below are approximate, because they depend on the molecular weight of the marker and on conventional rounding. Keep the precision the report gives you. A converted value is for orientation; the reported value in its reported unit is the one that belongs to the report.

## Conversion factors

Multiply the conventional value by the factor to get the SI value. Divide to go the other way.

| Marker | Conventional | SI | Multiply by |
| --- | --- | --- | --- |
| Glucose | mg/dL | mmol/L | 0.0555 |
| Total cholesterol, LDL, HDL | mg/dL | mmol/L | 0.0259 |
| Triglycerides | mg/dL | mmol/L | 0.0113 |
| Creatinine | mg/dL | umol/L | 88.4 |
| Uric acid | mg/dL | umol/L | 59.48 |
| Bilirubin | mg/dL | umol/L | 17.1 |
| Calcium | mg/dL | mmol/L | 0.2495 |
| Vitamin D (25-hydroxy) | ng/mL | nmol/L | 2.496 |
| Vitamin B12 | pg/mL | pmol/L | 0.738 |
| Testosterone | ng/dL | nmol/L | 0.0347 |
| Haemoglobin | g/dL | g/L | 10 |
| Ferritin | ng/mL | ug/L | 1 |

The factors follow [the lab report units guide](https://doctano.com/guides/lab-report-units) and standard molecular-weight conversions. HbA1c uses a separate equation and has its own [HbA1c calculator](https://doctano.com/tools/hba1c-calculator).

## How to use it

1. Find the value and the unit printed on the report.
2. Choose the marker. Different markers use different factors, even when the units look similar.
3. Choose the direction: conventional to SI, or SI to conventional.
4. Compare the converted value with a value in the same unit. Do not compare a converted number with a number in a different scale.

## What the result means, and what it does not

The result is the same measurement on the other scale. It does not tell you whether the value is in range, and it does not replace the range printed on the report. A conversion also does not correct for differences in assay, calibration, or sample handling between two laboratories.

This matters when two reports use different units. After conversion, the numbers can still differ for reasons that have nothing to do with the person. A small difference between two laboratories is not automatically a real change.

## Limitations

- **Approximate factors.** The factors are rounded, and the molecular weight used can vary slightly between sources.
- **Not every marker.** The table covers common markers, not every test on a report.
- **Assay differences remain.** A conversion changes the scale, not the method.
- **Rounding.** A laboratory may round a value before printing it, so a converted value can differ slightly from another printed value.
- **HbA1c is separate.** The percentage and mmol/mol scales use a different equation.

## What this page is not

This converter is a unit conversion. It is not a diagnosis, a range, a treatment recommendation, or medical advice. It does not replace the value, unit, or range on your report. Verify the original value and unit against the report and discuss the result with a qualified professional.

## Unit converter questions

**How do I convert mg/dL to mmol/L for cholesterol?**

Multiply the mg/dL value by 0.0259. Glucose uses a different factor, 0.0555, and triglycerides use 0.0113, because each marker has a different molecular weight. This converter applies the factor for the marker you choose.

**Why do laboratories use different units?**

Conventional units such as mg/dL are common in India and the United States, while SI units such as mmol/L are common in the United Kingdom and much of Europe. Units are conventions. The measurement is the same, and the scale is different.

**Does converting a unit make two labs comparable?**

No. A conversion puts the numbers on the same scale. Two laboratories can still use different assays and calibration, so a small difference may remain after conversion. Compare results from the same laboratory where possible.

**Why is HbA1c not in this converter?**

HbA1c uses a different kind of conversion between the NGSP percentage and the IFCC mmol/mol scale. It has its own calculator, which uses the NGSP master equation.

**What does x10^9/L mean on a blood count?**

It is the number of cells in a litre, in billions. It is the same count as x10^3/uL, which is how many laboratories write white cell and platelet counts. The two notations describe the same scale.

## Limits

**This is a conversion, not a diagnosis.** A converted value is not a result on your report and not a range. Use the value and range printed on the report, and discuss the result with a qualified professional.

## Links

- [Homepage](https://doctano.com/)
- [Lab report tracker](https://doctano.com/lab-report-tracker)
- [All tools](https://doctano.com/tools/)
- [Lab report units](https://doctano.com/guides/lab-report-units)
- [Fasting glucose](https://doctano.com/tests/fasting-glucose)
- [Total cholesterol](https://doctano.com/tests/total-cholesterol)
- [HbA1c calculator](https://doctano.com/tools/hba1c-calculator)
- [All guides](https://doctano.com/guides/)