PonyatnoHow it's calculated
All values are converted to mmol/L first: cholesterol in mg/dL is divided by 38.67, triglycerides by 88.57. The result card shows mg/dL too.
LDL (Friedewald) = total cholesterol − HDL − triglycerides / 2.2 (in mmol/L). It is only used when triglycerides are no higher than 4.5 mmol/L.
Non-HDL = total cholesterol − HDL. Atherogenic index = (total cholesterol − HDL) / HDL. AIP = log₁₀(triglycerides / HDL), both in mmol/L — in mg/dL the ratio would be different.
LDL and non-HDL ranges follow the 2019 ESC/EAS guidelines for people without raised cardiovascular risk; AIP ranges follow Dobiášová (2001).
What to know
What these numbers show
LDL is the main "bad" cholesterol: lowering it is what reduces the risk of heart attack and stroke. Non-HDL includes LDL and the other particles that build up in artery walls; it is especially useful when triglycerides are high and doesn't require fasting.
The atherogenic index (total minus HDL, divided by HDL) is a traditional ratio printed by labs in Eastern Europe. International guidelines don't use it, and the 3 cut-off is a convention. AIP reflects the triglyceride-to-HDL balance and, indirectly, how many small dense LDL particles there are.
Your goal depends on your risk
The cut-offs here are for people without raised risk. With diabetes, heart or vascular disease, kidney disease, inherited high cholesterol or several risk factors, LDL and non-HDL goals are considerably lower. Your doctor sets them based on your overall risk.
When the calculation is less accurate
Friedewald is inaccurate when triglycerides are high (which is why it is not used above 4.5 mmol/L), when LDL is very low, and when blood is drawn after a meal — triglycerides rise and LDL comes out too low. In these cases a directly measured LDL is better.
This calculator is a reference tool, not a diagnosis. Laboratory ranges differ, and the result depends on your health, medicines and other tests. Discuss it with your doctor.
FAQ
What is a normal LDL level?
For people without raised risk, the 2019 ESC goal is below 3 mmol/L. With higher risk the goals are lower, sometimes much lower — your doctor sets them.
Why is the LDL on my report different?
Your lab may measure LDL directly or use another equation (such as Martin–Hopkins or Sampson). Small differences are normal.
Do I need to fast for a cholesterol test?
Not for total cholesterol, HDL or non-HDL. For a Friedewald LDL, a 9–12 hour fast is better, because triglycerides rise after eating.
What is the atherogenic index?
It is the ratio of "bad" cholesterol (total minus HDL) to "good" HDL. Values up to 3 are usually considered typical. It is a traditional measure — doctors look first at LDL and non-HDL.
Is high cholesterol dangerous?
It causes no symptoms itself, but years of raised LDL speed up atherosclerosis. How much it matters for you depends on age, blood pressure, smoking and other factors — talk it through with your doctor.
Sources
Formulas and cut-offs follow clinical guidelines — see sources below.
- Friedewald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma. Clin Chem. 1972;18(6):499–502.
- Mach F et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias. Eur Heart J. 2020;41(1):111–188.
- Dobiášová M, Frohlich J. The plasma parameter log(TG/HDL-C) as an atherogenic index. Clin Biochem. 2001;34(7):583–588.