Calculate total to HDL cholesterol ratio.
The total-to-HDL cholesterol ratio divides total cholesterol by HDL cholesterol. Because HDL carries cholesterol away from artery walls, a higher HDL pulls the ratio down, and the ratio often tracks cardiovascular risk more closely than total cholesterol alone. Non-HDL cholesterol — total minus HDL — is shown alongside it because it captures every atherogenic particle in one number.
Total-to-HDL ratio
Ratio = total cholesterol / HDL cholesterol
Non-HDL cholesterol
Non-HDL = total cholesterol - HDL cholesterol
Educational estimate only. Not medical advice — discuss results with a qualified clinician before changing treatment, medication or exercise.
Below 3.5 is generally considered optimal and below 5 desirable. Between 5 and 7 is borderline, and above 7 is usually treated as high. The bands are population guides, not diagnoses.
Two people can share a total cholesterol of 200 mg/dL and have very different risk if one has HDL of 70 and the other 35. Dividing by HDL captures that difference in a single figure.
Total and HDL cholesterol are reasonably stable without fasting, which is why this ratio can be read from a non-fasting panel. Triglycerides and calculated LDL are the values that usually require a fast.