By Zencalcy Editorial TeamLast reviewed About us
Cholesterol ratios compare one lipid fraction with another, which can add context that a single number cannot. This calculator reports total cholesterol to HDL, LDL to HDL and triglyceride to HDL from mg/dL inputs, then places the total/HDL figure in commonly cited reference bands. Those bands are general guides, not a diagnosis or a treatment target.
Total/HDL, LDL/HDL and triglyceride/HDL ratios from one panel.
Total/HDL = total cholesterol ÷ HDL LDL/HDL = LDL cholesterol ÷ HDL TG/HDL = triglycerides ÷ HDL
All inputs must be in mg/dL. Common reference bands for total/HDL are below 3.5 (often called optimal), 3.5 to 5.0 (average) and above 5.0 (high). These bands vary between laboratories and guidelines, and a ratio cannot replace a full lipid panel interpreted alongside blood pressure, smoking status, diabetes and family history.
| Symbol | Meaning |
|---|---|
| Total/HDL | Total cholesterol divided by HDL cholesterol. |
| LDL/HDL | LDL cholesterol divided by HDL cholesterol. |
| TG/HDL | Triglycerides divided by HDL cholesterol. |
| Reference bands | Common total/HDL groupings, not diagnostic cutoffs. |
Total/HDL = 200 ÷ 50 = 4.00, which sits in the average band. LDL/HDL = 120 ÷ 50 = 2.40 and TG/HDL = 150 ÷ 50 = 3.00. All values are in mg/dL. The ratios add shape to the panel, but the same numbers would be interpreted differently for a smoker with diabetes than for a young person with no other risk factors.
A ratio compresses two measurements into one number, which makes patterns easier to see but removes detail. Total/HDL rises when total cholesterol rises or when HDL falls, and those are not equivalent events. The same is true of TG/HDL, which is sometimes used as a rough marker of insulin resistance: it can be elevated because triglycerides are high, because HDL is low, or both. Treat the ratio as a prompt to look back at the underlying fractions rather than as a standalone score. Reference bands also come from population studies and differ between guidelines, so a value just outside a band is not a clinical event. If a ratio concerns you, ask what the individual LDL, HDL and triglyceride values mean in your own risk context.
Continue with the Cholesterol Units Converter, LDL Calculator (Friedewald), or the VLDL Calculator — or browse more metabolic health tools and all health calculators.
Common reference bands describe below 3.5 as optimal, 3.5 to 5.0 as average and above 5.0 as high. These are broad groupings used in educational material, not a universal target. Your clinician may weigh the ratio differently depending on your other cardiovascular risk factors.
Lipid and metabolic calculations are screening aids, not diagnoses. Friedewald LDL is unreliable when triglycerides are high, and risk depends on blood pressure, smoking, diabetes, kidney disease and family history. Treatment decisions require a clinician and, in most cases, a full lipid panel.
Reference material used to build and check this calculator:
Last reviewed: September 2026. See how we build and check every tool on the about page.
Content updated: September 2026