What is the conversion factor between Lp(a) mg/dL and nmol/L?

There is no single exact factor. nmol/L counts particles while mg/dL measures the mass of the apo(a) protein, which varies with the apo(a) isoform you inherited. The commonly cited rule of thumb is about 2.15, but the real spread is roughly 2.0–2.7×, so the same sample can read up to ~2× apart depending on the assay. This tool shows a range, never a single number.

Which unit should I use for Lp(a)?

nmol/L is the modern, isoform-independent standard preferred by the 2026 guidelines because it counts particles. Prefer it, and if you retest, use the same lab and assay so your results are comparable.

Can I use a converted value to decide if I'm at risk?

No. Never use a converted value to make a decision near a threshold, because the conversion is imprecise. Read your risk band from the value in the unit your lab actually reported.

Tool

Lp(a) unit converter: mg/dL ↔ nmol/L

Lp(a) is reported in two units that measure different things — and they don’t cleanly convert. This tool gives you the approximate equivalent as a range, shows which risk band your number falls in, and is loud about the one rule that matters: never use a converted value to make a decision near a threshold.

Your Lp(a) result

Value (nmol/L)

Enter your Lp(a) value to see the approximate equivalent in the other unit and which risk band it falls in.

For the full picture — whether to test, how to read your number, and what you can actually do about a high result, see the Lp(a) guide.