Lp(a) Unit Converter
Enter your Lp(a) result in whichever unit your laboratory used. US labs often report mg/dL, European and newer assays usually report nmol/L, which is why the same person can see two very different-looking numbers across two reports.
Educational tool, not a diagnosis. The practical advice matters more than the arithmetic here: stay on one unit and one assay when tracking Lp(a) over time, because a change in reported value between labs is more likely to be a units or method artifact than a real biological change. Lp(a) is also largely genetically determined and stable through life, so it is usually measured once rather than monitored — a rising result is more often a lab difference than a real trend. Thresholds vary between guidelines; interpret with the range printed on your own report and with your physician.
Why there is no exact conversion
This is the part every other converter skips. Milligrams per deciliter measures the total mass of Lp(a) in your blood. Nanomoles per litre counts how many Lp(a) particles are there. Converting between them requires knowing the mass of one particle — and that is not a constant, because the apo(a) protein comes in different sizes from person to person, determined genetically.
So a conversion factor is a population average applied to an individual. It gets you in the right neighbourhood, which is genuinely useful when you are staring at a number in an unfamiliar unit, but it is not a translation. Presenting one decimal place of false precision would be worse than showing the range honestly.
nmol/L to mg/dL: the reference table
The converter above handles any value you type. The table below covers the reference points most people arrive with, using the two approximations in common circulation — dividing by 2.5 at one end and by 2.15 at the other. Read the span, not either edge.
| Lp(a) in nmol/L | Approximate mg/dL | Where that sits |
|---|---|---|
| 25 nmol/L | 10.0 - 11.6 mg/dL | Below common thresholds |
| 50 nmol/L | 20.0 - 23.3 mg/dL | Below common thresholds |
| 75 nmol/L | 30.0 - 34.9 mg/dL | Start of the intermediate zone |
| 100 nmol/L | 40.0 - 46.5 mg/dL | Intermediate |
| 125 nmol/L | 50.0 - 58.1 mg/dL | The commonly cited threshold |
| 150 nmol/L | 60.0 - 69.8 mg/dL | Elevated |
| 200 nmol/L | 80.0 - 93.0 mg/dL | Elevated |
| 250 nmol/L | 100.0 - 116.3 mg/dL | Elevated |
| 300 nmol/L | 120.0 - 139.5 mg/dL | Elevated |
| 400 nmol/L | 160.0 - 186.0 mg/dL | Elevated |
mg/dL to nmol/L: the same table in reverse
US labs still report Lp(a) in mg/dL, while newer assays and most European labs report nmol/L. If your older result is in mg/dL and your new one is not, this is the direction you need — multiply by 2.15 to 2.5. It is the same approximation, with the same limits.
| Lp(a) in mg/dL | Approximate nmol/L | Where that sits |
|---|---|---|
| 10 mg/dL | 22 - 25 nmol/L | Below common thresholds |
| 20 mg/dL | 43 - 50 nmol/L | Below common thresholds |
| 30 mg/dL | 65 - 75 nmol/L | Start of the intermediate zone |
| 40 mg/dL | 86 - 100 nmol/L | Intermediate |
| 50 mg/dL | 108 - 125 nmol/L | The commonly cited threshold |
| 60 mg/dL | 129 - 150 nmol/L | Elevated |
| 75 mg/dL | 161 - 188 nmol/L | Elevated |
| 100 mg/dL | 215 - 250 nmol/L | Elevated |
| 150 mg/dL | 323 - 375 nmol/L | Elevated |
One consequence worth stating plainly: because the conversion is a range, a result that lands near the threshold in one unit can land on the other side of it in the other. An Lp(a) of 120 nmol/L converts to roughly 48 to 56 mg/dL — below the 50 mg/dL line, or above it, depending which factor you pick. That is a limit of the units, not of the measurement, and it is a reason to read a borderline Lp(a) alongside the rest of your cardiovascular picture rather than as a pass or fail.
Converting other markers between nmol/L, mmol/L and mg/dL
If you landed here for a different blood test, the good news is that your conversion is exact. Every other analyte has a fixed factor, set by its molecular weight — which is precisely what Lp(a) lacks. The factors below are the standard ones:
| Marker | Conversion |
|---|---|
| 25-OH vitamin D | nmol/L divided by 2.496 = ng/mL. A level of 75 nmol/L is 30 ng/mL — what 30 actually means. |
| Total testosterone | nmol/L multiplied by 28.84 = ng/dL. Feeds the free testosterone calculator. |
| Fasting glucose | mmol/L multiplied by 18.02 = mg/dL. |
| Triglycerides | mmol/L multiplied by 88.57 = mg/dL. Both are inputs to the TyG index calculator. |
| Total, LDL and HDL cholesterol | mmol/L multiplied by 38.67 = mg/dL. |
| Fasting insulin | pmol/L divided by 6.00 = µIU/mL, the unit the HOMA-IR calculator expects. |
| Creatinine | µmol/L multiplied by 0.0113 = mg/dL. |
| Ferritin | No conversion needed: 1 µg/L and 1 ng/mL are the same quantity. |
What actually matters about Lp(a)
Lp(a) is an independent, largely inherited cardiovascular risk factor — the fuller picture is in what a high Lp(a) means. Because you cannot change it much through lifestyle, an elevated result is best read as a reason to be more deliberate about the risks you can change: ApoB, blood pressure, and the rest of the modifiable lipid picture. It is also worth knowing that an elevated Lp(a) is a reason for first-degree relatives to be tested.
Frequently asked questions
- How do you convert Lp(a) from nmol/L to mg/dL?
- There is no exact conversion, and any calculator giving you a single number is overstating its precision. The two units measure different things: mg/dL is the mass of the particle and nmol/L is the number of particles, and apo(a) particle size varies between individuals. Commonly used approximations divide nmol/L by somewhere between 2.15 and 2.5, which is why this tool returns a range.
- How do you convert mg/dL to nmol/L?
- Multiply by somewhere between 2.15 and 2.5. An Lp(a) of 50 mg/dL works out to roughly 108 to 125 nmol/L. The same caveat applies in this direction: the factor is a population average applied to one person, not a fixed constant.
- What is 125 nmol/L of Lp(a) in mg/dL?
- Roughly 50 to 58 mg/dL. Those two numbers, 125 nmol/L and 50 mg/dL, are the values most guidelines quote for elevated Lp(a), which is why they are often treated as equivalent. That pairing comes from how the threshold was defined in each unit rather than from an exact conversion between them.
- What Lp(a) level is considered high?
- The thresholds most often cited are roughly 125 nmol/L or 50 mg/dL, with an intermediate zone below that. Guidelines differ, and because the unit conversion is imprecise the two thresholds do not map onto each other perfectly. Interpret against the reference range printed on your own report.
- Does the same nmol/L to mg/dL factor work for other blood tests?
- No. Every other analyte has a fixed factor set by its molecular weight: 25-OH vitamin D in nmol/L divides by about 2.5 to give ng/mL, total testosterone in nmol/L multiplies by 28.84 to give ng/dL, glucose in mmol/L multiplies by 18.02 to give mg/dL. Lp(a) is the exception, because the quantity that varies is the mass of the particle itself. The conversion table on this page covers the markers most often reported in both systems.
- Why did my Lp(a) change between two tests?
- Most often it did not. Lp(a) is largely genetically determined and stable across adult life, so a different number between two labs is more likely to reflect a change in units or assay method than a real biological change. This is the main practical reason to stay with one lab and one unit when tracking it.
- Should I retest my Lp(a)?
- Usually not. Because the level is inherited and stable, most guidance treats Lp(a) as a once-in-a-lifetime measurement rather than something to monitor. The exception is a clinician-directed retest, for example to confirm an unexpectedly high first result or on a different assay.
- Does Merios store these numbers?
- No. The converter runs entirely in your browser. Your inputs never leave your device and are not sent to a server.
Track this in Merios
Stop converting the same number by hand every time you change labs.
Merios reads the units off each report you upload and keeps every marker on one scale, so a panel in nmol/L and a panel in mg/dL sit on the same curve instead of looking like two different people.
References: Kronenberg F, Mora S, Stroes ESG, et al. Lipoprotein(a) in atherosclerotic cardiovascular disease and aortic valve stenosis: a European Atherosclerosis Society consensus statement. Eur Heart J 2022;43(39):3925-3946. · Marcovina SM, Albers JJ. Lipoprotein (a) measurements for clinical application. J Lipid Res 2016;57(4):526-537. · Tsimikas S. A test in context: lipoprotein(a). J Am Coll Cardiol 2017;69(6):692-711. · Educational tool, not a diagnosis; interpret any result with the reference range printed on your own report and with your physician.