Non-HDL cholesterol is calculated by subtracting HDL cholesterol from total cholesterol. It represents the combined cholesterol content of all the atherogenic lipoprotein particles — LDL, VLDL, IDL, and Lp(a) — making it a broader and arguably more complete measure of atherogenic cholesterol than LDL alone.

Non-HDL cholesterol has several advantages over LDL: it does not require fasting, it captures all atherogenic particles including triglyceride-rich remnant particles, and it may be a better predictor of cardiovascular risk than LDL alone. It is increasingly recommended in cardiovascular risk guidelines as a primary treatment target alongside or instead of LDL, particularly in people with high triglycerides where calculated LDL can be unreliable.