Cholesterol Ratio Calculator
Calculate your total cholesterol/HDL (TC/HDL), LDL/HDL, triglyceride/HDL (TG/HDL) and non-HDL cholesterol from a standard lipid panel. Use mg/dL or mmol/L and see the formulas behind each result.
Ratios are only part of the picture. Current cholesterol management places greater emphasis on LDL-C, non-HDL-C and overall cardiovascular risk than on cholesterol ratios alone. This calculator helps you understand the numbers; it does not diagnose heart disease or decide whether you need treatment.
Your lipid summary will appear here
TC/HDL and non-HDL need only total cholesterol and HDL. More results unlock when you add LDL or triglycerides.
How to Calculate Cholesterol Ratios
A standard lipid panel can be used to calculate several related values. The most searched is the total cholesterol-to-HDL ratio, but LDL/HDL, TG/HDL and non-HDL cholesterol answer different questions.
TC/HDL
Total cholesterol ÷ HDL
LDL/HDL
LDL cholesterol ÷ HDL
TG/HDL
Triglycerides ÷ HDL
Non-HDL-C
Total cholesterol − HDL
Example: if total cholesterol is 200 mg/dL and HDL is 50 mg/dL, the TC/HDL ratio is 200 ÷ 50 = 4.0, commonly written as 4.0:1. Non-HDL cholesterol from the same two values is 150 mg/dL.
What Is a Good Cholesterol Ratio?
For the TC/HDL ratio, lower values are generally more favorable than higher values. A ratio around 3.5:1 or lower is often used as a favorable reference. That does not mean a ratio above a single cutoff automatically equals “high heart risk,” and a favorable ratio does not cancel out an elevated LDL-C level.
This is an educational spectrum, not a diagnostic risk scale. Your absolute cardiovascular risk depends on more than a cholesterol ratio.
TC/HDL vs LDL/HDL vs TG/HDL
| Measure | Formula | What it tells you | Important limitation |
|---|---|---|---|
| TC/HDL | TC ÷ HDL | Relationship between total cholesterol and HDL. | Can look favorable even when LDL-C still deserves attention. |
| LDL/HDL | LDL ÷ HDL | Relationship between LDL-C and HDL-C. | Does not replace the LDL-C value or a risk-based LDL goal. |
| TG/HDL | TG ÷ HDL | A lipid relationship studied in metabolic and cardiovascular research. | Not a diagnostic test for insulin resistance. |
TC/HDL is also sometimes described as a cholesterol ratio, cardiac risk ratio, coronary risk ratio or Castelli Risk Index I. LDL/HDL is sometimes called Castelli Risk Index II. These names do not turn the ratios into standalone risk calculators.
Non-HDL-C = Total cholesterol − HDL-C. It represents cholesterol carried by lipoproteins other than HDL, including atherogenic particles.
The 2026 ACC/AHA dyslipidemia guideline uses both LDL-C and non-HDL-C treatment goals, with targets depending on cardiovascular-risk context. That is why this page shows non-HDL alongside ratios rather than treating TC/HDL as the only important result.
Understanding the Numbers on a Lipid Panel
| Measure | General reference | Context |
|---|---|---|
| Total cholesterol | Often <200 mg/dL | A laboratory measure of cholesterol carried across multiple lipoprotein particles. |
| LDL-C | Goals are risk-dependent | A major treatment target. Higher-risk people may have substantially lower recommended goals. |
| HDL-C | Interpreted with the full lipid profile | Higher HDL is often associated with lower risk, but it should not be used alone or treated as cancelling high LDL. |
| Triglycerides | Often <150 mg/dL | Elevated levels can add cardiovascular and metabolic context; very high levels have additional clinical implications. |
These are broad educational reference points, not personalized treatment targets. LDL-C and non-HDL-C goals depend on cardiovascular history and estimated risk.
The historical Friedewald equation is:
LDL-C = Total cholesterol − HDL-C − (Triglycerides ÷ 5)
That equation is still useful for understanding older calculated-LDL results, but it should not be presented as the best modern estimation method in every situation.
The 2026 ACC/AHA Guideline on the Management of Dyslipidemia prefers newer LDL-C estimation methods such as Martin/Hopkins or Sampson/NIH when LDL-C is estimated from a standard lipid profile. If your laboratory already reports LDL-C, use the laboratory value rather than replacing it with a simple web calculation.
Cholesterol mg/dL to mmol/L Conversion
The conversion factor is different for cholesterol and triglycerides. Do not use the triglyceride factor for LDL, HDL or total cholesterol.
Total cholesterol, LDL & HDL
mg/dL × 0.02586 = mmol/L
mmol/L × 38.67 = mg/dL
Triglycerides
mg/dL × 0.01129 = mmol/L
mmol/L × 88.57 = mg/dL
A Cholesterol Ratio Is Not Your Heart-Risk Score
Cholesterol is only one part of cardiovascular risk. Age, blood pressure, smoking, diabetes, kidney and metabolic health, cardiovascular history and other risk-enhancing factors can change how the same LDL-C result is interpreted.
The 2026 ACC/AHA dyslipidemia guideline recommends the newer PREVENT-ASCVD equations for appropriate primary-prevention risk assessment in adults aged 30–79, replacing the older Pooled Cohort Equations for that purpose.
Explore cardiovascular riskNote: follow the methodology stated on that calculator. Do not assume an older ASCVD calculator implements PREVENT unless its algorithm has specifically been updated.
How to Improve an Unfavorable Lipid Profile
The useful target is usually the overall lipid profile and cardiovascular risk—not forcing one ratio toward a particular number.
- Favor fiber-rich foods such as vegetables, fruit, beans, whole grains and other minimally processed foods.
- Replace some saturated fats with unsaturated fats when appropriate.
- Build regular physical activity into your week.
- Avoid tobacco and nicotine exposure.
- Work toward a weight and waist trend that supports your metabolic health when weight loss is appropriate.
- Take prescribed lipid-lowering medication as directed and discuss treatment changes with your clinician.
Tracking Cholesterol During Weight Loss or GLP-1 Therapy
Weight loss can change triglycerides, LDL-C and HDL-C differently from person to person. If you use a GLP-1 medication, do not assume that losing weight guarantees a particular cholesterol response. Compare actual laboratory results over time and continue any cholesterol treatment or follow-up recommended by your clinician.
Track the trend between lab tests
Keep cholesterol, weight and glucose results together so changes are easier to compare over time.
Limitations of Cholesterol Ratio Calculators
- A ratio cannot diagnose coronary artery disease or predict an individual heart attack or stroke by itself.
- A favorable ratio does not make an elevated LDL-C irrelevant.
- LDL-C and non-HDL-C treatment goals depend on cardiovascular-risk context.
- TG/HDL is not a diagnostic test for insulin resistance.
- Calculated LDL depends on the equation used; modern laboratory methods may differ from the historical Friedewald estimate.
- Use the values and units exactly as reported by your laboratory whenever possible.
Methodology and Medical Sources
Calqulate calculates ratios arithmetically from the lipid values you enter. Non-HDL-C is calculated as total cholesterol minus HDL-C. We separate those calculations from clinical risk assessment because a mathematical ratio is not the same as a treatment recommendation.
Medical interpretation on this page was reviewed against the 2026 ACC/AHA Guideline on the Management of Dyslipidemia, including its return to LDL-C and non-HDL-C goals and its use of PREVENT-ASCVD for contemporary primary-prevention risk assessment.
Related Cardio Health Calculators
Explore the rest of our cardio health tools — each one adds a different piece of the picture.
Frequently Asked Questions
Common questions and answers about this calculator.
What is a good cholesterol ratio?
For total cholesterol divided by HDL (TC/HDL), a lower ratio is generally more favorable than a higher one. A value around 3.5 or lower is often used as a favorable reference, but the ratio should not be used by itself to decide whether your cardiovascular risk is low or high. LDL-C, non-HDL-C, triglycerides and your overall cardiovascular risk also matter.
How do you calculate the cholesterol to HDL ratio?
Divide total cholesterol by HDL cholesterol. For example, total cholesterol of 200 mg/dL and HDL of 50 mg/dL gives a TC/HDL ratio of 4.0, commonly written as 4.0:1.
How do you calculate LDL to HDL ratio?
Divide LDL cholesterol by HDL cholesterol. For example, LDL of 110 mg/dL and HDL of 50 mg/dL gives an LDL/HDL ratio of 2.2:1. This ratio is supplementary and should not replace interpretation of the LDL-C value itself.
How do you calculate triglyceride to HDL ratio?
Divide triglycerides by HDL when both values use the same conventional unit system. TG/HDL has been studied as a metabolic and cardiovascular marker, but it is not a diagnostic test for insulin resistance and should not be interpreted in isolation.
How do I calculate non-HDL cholesterol?
Subtract HDL cholesterol from total cholesterol: non-HDL-C = total cholesterol - HDL-C. Non-HDL-C represents cholesterol carried by atherogenic lipoproteins other than HDL and is used alongside LDL-C in current dyslipidemia guidance.
How do I calculate LDL cholesterol manually?
The historical Friedewald equation is LDL-C = total cholesterol - HDL-C - (triglycerides / 5) when values are in mg/dL. However, the 2026 ACC/AHA dyslipidemia guideline prefers newer LDL-C estimation methods such as Martin/Hopkins or Sampson/NIH when LDL-C is estimated from a standard lipid profile. Use your laboratory-reported LDL-C when available.
Can I calculate cholesterol in mmol/L?
Yes. Cholesterol values such as total cholesterol, HDL-C and LDL-C can be converted between mg/dL and mmol/L using different conversion factors from triglycerides. For cholesterol, mg/dL × 0.02586 gives mmol/L. For triglycerides, mg/dL × 0.01129 gives mmol/L.
Is a cholesterol ratio the same as cardiovascular risk?
No. A cholesterol ratio describes relationships between lipid values; it does not calculate your absolute chance of heart attack or stroke. Current cardiovascular risk assessment also considers factors such as age, blood pressure, smoking, diabetes, kidney and metabolic health, and other risk enhancers.
What if both HDL and LDL are high?
A higher HDL value does not cancel out an elevated LDL-C value. LDL-C and non-HDL-C should still be assessed in the context of your overall cardiovascular risk and any treatment targets recommended for you.
How often should cholesterol be checked?
Testing frequency depends on age, previous results, cardiovascular risk, medical conditions and treatment. Follow the testing interval recommended by your clinician rather than relying on one universal schedule.
Tool Information
August 2026
Dr. Jaydeep Sanghani
Meet Akabari
Dr. Jaydeep Sanghani
MBBS, MD, DNB(Anaesth.), PDCC(CCM), DrNB(CCM)
AIIMS Bhubaneswar · AIIMS Rishikesh
Critical care specialist and anesthesiologist with advanced training from AIIMS. Reviews health calculators at Calqulate to ensure medical accuracy and evidence-based standards.
About the authors
