Cholesterol Ratio Calculator

A cholesterol ratio calculator computes the mathematical relationships between the different components of your cholesterol panel — Total Cholesterol, LDL (low-density lipoprotein, "bad" cholesterol), HDL (high-density lipoprotein, "good" cholesterol), and Triglycerides. Research shows that cholesterol ratios are stronger predictors of cardiovascular disease risk than any single cholesterol value alone. Our cholesterol ratio calculator computes all four clinically relevant ratios — Total/HDL, LDL/HDL, Triglycerides/HDL, and Non-HDL cholesterol — with risk interpretation based on AHA/ACC guidelines, running locally in your browser with no data sent to any server.

1. 1. Enter Your Cholesterol Panel Values: Enter your Total Cholesterol, LDL, HDL, and Triglycerides from your blood test report. Select mg/dL (US standard) or mmol/L (UK, Canada, Australia). The reference ranges and risk thresholds update automatically for your chosen unit.
2. 2. Instant Multi-Ratio Calculation: Click Calculate Ratios and the calculator instantly computes all four ratios — Total/HDL, LDL/HDL, Triglycerides/HDL, and Non-HDL cholesterol. All calculations happen locally in your browser with complete privacy.
3. 3. View Risk Interpretation for Each Ratio: Each ratio is displayed with a risk label (Optimal, Borderline, High Risk, etc.), a visual risk bar, and a brief explanation based on AHA/ACC guidelines. A full breakdown table and reference ranges are also shown.

• Total Cholesterol / HDL Ratio (Castelli Risk Index I): The Total/HDL ratio is one of the strongest predictors of cardiovascular risk. A ratio below 3.5 is optimal; below 5.0 is average risk; above 6.0 indicates significantly elevated risk. This ratio is sometimes called the Castelli Risk Index I and is widely used in clinical practice.
• LDL / HDL Ratio (Castelli Risk Index II): The LDL/HDL ratio (Castelli Risk Index II) measures the balance between "bad" LDL cholesterol and "good" HDL cholesterol. A ratio below 2.0 is optimal; below 3.0 is near optimal; above 4.0 indicates high cardiovascular risk. This ratio is particularly useful for assessing atherosclerosis risk.
• Triglycerides / HDL Ratio (TG/HDL): The TG/HDL ratio is a widely used proxy for insulin resistance and metabolic syndrome. In mg/dL, a ratio below 2.0 indicates low risk; above 4.0 indicates high risk. In mmol/L, the thresholds are 0.87 and 1.74 respectively. A high TG/HDL ratio is associated with small, dense LDL particles — the most atherogenic form.
• Non-HDL Cholesterol: Non-HDL cholesterol = Total Cholesterol − HDL. It captures all atherogenic lipoproteins (LDL, VLDL, IDL, Lp(a)) in a single number. The AHA/ACC guidelines consider Non-HDL a better predictor of cardiovascular risk than LDL alone, especially in people with high triglycerides. Optimal Non-HDL is below 130 mg/dL (3.37 mmol/L).

• Total/HDL Ratio: The Castelli Risk Index I — one of the strongest single predictors of cardiovascular disease risk.
• LDL/HDL Ratio: The Castelli Risk Index II — measures the balance between atherogenic and protective cholesterol.
• Triglycerides/HDL Ratio: A proxy for insulin resistance and metabolic syndrome risk.
• Non-HDL Cholesterol: Total minus HDL — captures all atherogenic lipoproteins in a single value.
• Risk Interpretation: Each ratio is labelled Optimal, Near Optimal, Borderline, High Risk, or Very High Risk based on AHA/ACC guidelines, with a visual risk bar.