Cholesterol Ratio Calculator
Enter your lipid panel values to calculate TC/HDL, LDL/HDL, non-HDL cholesterol and the triglycerides/HDL ratio, each compared with published reference bands.
CalcVita. (2026). Cholesterol Ratio Calculator — TC/HDL. CalcVita. Retrieved October 17, 2026, from https://calcvita.com/en/calculators/cholesterol-ratio
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Cholesterol Ratios Explained: TC/HDL, LDL/HDL & Cardiovascular Risk
Your cholesterol ratio tells more about heart disease risk than total cholesterol alone. Learn what TC/HDL, LDL/HDL, non-HDL, and TG/HDL ratios mean, which reference values are used to interpret them, and which lifestyle changes lower your numbers.
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How It Works
Enter your total cholesterol, HDL, LDL and triglycerides from a standard lipid panel. The calculator computes four ratios and shows each against reference bands; the overall level is the worst of the four.
Methodology & Formulas
TC/HDL ratio = total cholesterol / HDL. LDL/HDL ratio = LDL / HDL. Non-HDL cholesterol = total cholesterol − HDL (the cholesterol in all atherogenic lipoproteins: LDL, VLDL, IDL, Lp(a)). Triglycerides/HDL ratio = triglycerides / HDL, both in mg/dL (mmol/L inputs are converted first: ×38.67 for cholesterol, ×88.57 for triglycerides). In the Framingham Heart Study, Castelli (1988) described TC/HDL as the best simple test for predicting coronary disease, and the review by Millán et al. (2009) concludes that it predicts coronary risk better than total, LDL or HDL cholesterol used on their own.
Risk Thresholds
TC/HDL: high from 5.0 (Millán 2009 risk level for men; for women it is above 4.5); optimal <3.5 and very high ≥6.0 are orientative. LDL/HDL: high from 3.5 (Millán 2009, men; women above 3.0); optimal <2.5 and very high ≥4.5 are orientative. Non-HDL: optimal <130 mg/dL, borderline 130–159, high 160–189, very high ≥190 — orientative bands; the 2018 AHA/ACC guideline uses 190–219 mg/dL as a risk-enhancing factor. TG/HDL (mg/dL): high from 3.0, the cut-point McLaughlin et al. (2003) found for insulin resistance in overweight adults; the other bands are orientative. The calculator does not ask for sex, so it applies the men’s thresholds.
Scientific Sources
- Millán J et al. Lipoprotein ratios: Physiological significance and clinical usefulness in cardiovascular prevention. Vasc Health Risk Manag. 2009;5:757-765. PMID 19774217
- McLaughlin T et al. Use of metabolic markers to identify overweight individuals who are insulin resistant. Ann Intern Med. 2003;139:802-809. PMID 14623617
- Dobiásová M, Frohlich J. The plasma parameter log (TG/HDL-C) as an atherogenic index. Clin Biochem. 2001;34:583-588. PMID 11738396
- Grundy SM et al. 2018 AHA/ACC Guideline on the Management of Blood Cholesterol. Circulation. 2019;139:e1082-e1143. PMID 30586774
- Castelli WP. Cholesterol and lipids in the risk of coronary artery disease — the Framingham Heart Study. Can J Cardiol. 1988;4 Suppl A:5A-10A. PMID 3179802
Frequently Asked Questions
What is the TC/HDL cholesterol ratio and why does it matter?▾
The TC/HDL ratio (total cholesterol divided by HDL cholesterol, also called the Castelli index) sums up in one number the balance between cholesterol carried in atherogenic particles and HDL, which carries excess cholesterol back to the liver. In the Framingham Heart Study, Castelli (1988) described it as the best simple test for predicting coronary artery disease. A 2009 review (Millán et al.) sets the primary-prevention risk level above 5.0 in men and above 4.5 in women. This calculator flags 5.0 or more as high; the "optimal" band below 3.5 is orientative.
What is the LDL/HDL ratio and what levels are considered safe?▾
The LDL/HDL ratio compares "bad" cholesterol (LDL, which builds up in artery walls) with "good" cholesterol (HDL, which removes it). Millán et al. (2009) set the primary-prevention risk level above 3.5 in men and above 3.0 in women. This calculator flags 3.5 or more as high; the "optimal" band below 2.5 is orientative. Lowering LDL and raising HDL both bring the ratio down.
What is non-HDL cholesterol and how is it calculated?▾
Non-HDL cholesterol = total cholesterol − HDL cholesterol. It captures the cholesterol in every atherogenic lipoprotein: LDL, VLDL, IDL and lipoprotein(a). The 2018 AHA/ACC cholesterol guideline counts a non-HDL of 190–219 mg/dL (4.9–5.6 mmol/L) as a risk-enhancing factor. The bands this calculator shows (under 130 mg/dL optimal, 130–159 borderline, 160–189 high, 190 or more very high) are orientative, not guideline categories.
What is the triglycerides/HDL ratio?▾
It is triglycerides divided by HDL, both in mg/dL — the number changes if you divide values in mmol/L, so the calculator always converts to mg/dL first. It is related to, but not the same as, the atherogenic index of plasma (AIP), which Dobiásová defined as the logarithm of the molar ratio. In overweight adults, McLaughlin et al. (2003) found that a ratio of 3.0 or more identified insulin resistance (sensitivity 64%, specificity 68%). The calculator flags 3.0 or more as high; the low-risk band below 2.0 is orientative.
How can I improve my cholesterol ratios?▾
Regular aerobic exercise, replacing saturated fats with unsaturated ones (olive oil, nuts, oily fish), losing excess weight, quitting smoking and cutting down on refined carbohydrates and sugar (which raise triglycerides) all improve these ratios. If lifestyle changes are not enough, your doctor may prescribe a statin or another lipid-lowering drug.
How often should I check my cholesterol levels?▾
The right interval depends on your overall risk, so agree it with your doctor. The 2018 AHA/ACC guideline notes that screening can be done with a fasting or a non-fasting blood sample. A standard lipid panel reports total cholesterol, HDL, LDL (calculated or measured) and triglycerides — the four values this calculator needs.