Cholesterol Ratio Calculator

Q: What is a good TC/HDL ratio?

A good TC/HDL ratio is below 3.5 . This means your risk for heart disease is low. A ratio between 3.5 and 5.0 is moderate risk. A ratio above 5.0 is high risk. The lower the number, the better your heart health.

Q: How do I switch between mg/dL and mmol/L?

Click the mg/dL or mmol/L button at the top of the calculator. All your entered values will convert automatically. Make sure to pick the unit that matches your lab report before entering numbers.

Updated May 25, 2026 By Jehan Wadia

Introduction

A cholesterol ratio calculator helps you understand your heart disease risk by comparing different types of cholesterol in your blood. Your doctor may test your total cholesterol, HDL (good cholesterol), LDL (bad cholesterol), and triglycerides. Each number on its own tells part of the story, but the ratios between them give a clearer picture of your heart health. For example, a high total cholesterol number might not be dangerous if your HDL is also high. This tool takes your cholesterol numbers and calculates three key ratios: TC/HDL, LDL/HDL, and TG/HDL. It also finds your non-HDL cholesterol and VLDL estimate. You can enter values in mg/dL or mmol/L, and if you only have three of the four values, the calculator will figure out the missing one using the Friedewald equation.

Simply enter your cholesterol lab results below, choose your units and biological sex, and the calculator will show your ratios, risk levels, and how your numbers compare to standard guidelines. Use this tool to better understand your lipid panel results before or after talking with your doctor.

How to Use Our Cholesterol Ratio Calculator

Enter your cholesterol numbers from a blood test, and this tool will calculate your key cholesterol ratios, risk levels, and overall heart health assessment.

Units: Pick mg/dL or mmol/L to match the units on your lab report. All your numbers will convert automatically if you switch.

Sex: Choose Male, Female, or Prefer not to say. This affects how your HDL cholesterol level is classified, since healthy HDL ranges differ between men and women.

Total Cholesterol: Enter your total cholesterol number from your blood test. This is the combined amount of all cholesterol in your blood.

HDL Cholesterol: Enter your HDL or "good" cholesterol number. Higher HDL levels help protect your heart.

LDL Cholesterol: Enter your LDL or "bad" cholesterol number. Lower LDL levels are better for heart health.

Triglycerides: Enter your triglyceride number. These are a type of fat found in your blood.

Tip: You only need to fill in 3 of the 4 cholesterol fields. Leave one blank, and the calculator will figure it out for you using the Friedewald formula.

Click Calculate to see your TC/HDL ratio, LDL/HDL ratio, TG/HDL ratio, non-HDL cholesterol, risk gauges, charts, and reference tables. Click Reset to clear your inputs and start over.

What Is a Cholesterol Ratio?

A cholesterol ratio compares different types of cholesterol in your blood. Your doctor uses these ratios to see how likely you are to develop heart disease. The most common ratio is total cholesterol divided by HDL cholesterol. A lower number means a lower risk for your heart. If you want to explore how ratios work in a general mathematical sense, our Ratio Calculator can help you understand the concept further.

Types of Cholesterol

Your blood carries cholesterol in different packages:

Total Cholesterol (TC) – The total amount of all cholesterol in your blood.
HDL (High-Density Lipoprotein) – Often called "good" cholesterol. It helps remove bad cholesterol from your arteries. Higher HDL is better.
LDL (Low-Density Lipoprotein) – Often called "bad" cholesterol. Too much LDL builds up in your artery walls and can lead to heart attack or stroke. Lower LDL is better.
Triglycerides (TG) – A type of fat in your blood. Your body turns extra calories, sugar, and alcohol into triglycerides. High levels raise your heart disease risk.
VLDL (Very Low-Density Lipoprotein) – Another "bad" type that carries triglycerides. It is estimated by dividing your triglycerides by 5.
Non-HDL Cholesterol – This is your total cholesterol minus your HDL. It includes all the "bad" types together, making it a useful single number for risk assessment.

Key Cholesterol Ratios Explained

TC/HDL Ratio

This ratio divides your total cholesterol by your HDL. A result below 3.5 is considered low risk. A result between 3.5 and 5.0 is moderate risk. A result above 5.0 is high risk. The American Heart Association says this ratio is a helpful tool for estimating heart disease risk.

LDL/HDL Ratio

This ratio divides your LDL by your HDL. It shows the balance between bad and good cholesterol. A result below 2.0 is ideal. A result between 2.0 and 3.5 is moderate risk. A result above 3.5 is high risk.

TG/HDL Ratio

This ratio divides your triglycerides by your HDL. Research shows it can predict insulin resistance and heart disease risk. A result below 2.0 is low risk. A result above 4.0 is high risk.

The Friedewald Formula

If you know three of the four cholesterol values, the missing one can be estimated using the Friedewald equation:

LDL = Total Cholesterol − HDL − (Triglycerides ÷ 5)

This formula works when triglycerides are below 400 mg/dL (4.52 mmol/L). Most labs use this formula to calculate your LDL. This calculator uses it automatically when you leave one field blank.

What Are Healthy Cholesterol Levels?

According to the National Institutes of Health and the American Heart Association, healthy cholesterol levels for most adults in mg/dL are:

Total Cholesterol: Below 200
HDL: 60 or higher (below 40 for men or below 50 for women is a risk factor)
LDL: Below 100 is optimal
Triglycerides: Below 150
Non-HDL: Below 130

Why Ratios Matter More Than Single Numbers

A single cholesterol number does not tell the full story. For example, a person with high total cholesterol but very high HDL may actually have low heart risk. Ratios capture the balance between protective and harmful cholesterol, giving a clearer picture of cardiovascular risk than any one value alone. Maintaining healthy cholesterol ratios goes hand in hand with other health metrics. Tracking your waist-to-hip ratio or waist-to-height ratio can also help assess cardiovascular risk. Monitoring your body fat percentage and keeping your weight in check with tools like our Ideal Body Weight Calculator or Weight Loss Calculator supports better cholesterol levels over time.

Exercise is one of the most effective ways to raise HDL and improve cholesterol ratios. If you're tracking fitness activity, tools like our Calories Burned Calculator, Heart Rate Zone Calculator, Target Heart Rate Calculator, and Max Heart Rate Calculator can help you optimize your workouts. Runners may find our Running Pace Calculator or Marathon Pace Calculator useful for planning cardio sessions that benefit heart health. Your VO2 Max is another valuable indicator of cardiovascular fitness.

Diet also plays a central role in managing cholesterol. Understanding your nutritional intake with our Calorie Calculator, Macro Calculator, or Protein Calculator can help you make heart-healthy dietary choices. Tracking your fiber intake is especially relevant since soluble fiber helps lower LDL cholesterol. If your doctor has also checked your blood sugar levels alongside your lipid panel, our A1C Calculator can help you monitor that related metric, as diabetes and high cholesterol often go together.

Important Notes

This calculator is for educational purposes only. It does not replace medical advice. Cholesterol levels should be interpreted by your doctor along with other risk factors like age, blood pressure, smoking, diabetes, and family history. Other health calculators such as the BMR Calculator, TDEE Calculator, BSA Calculator, and GFR Calculator can provide additional health insights, but always talk to a healthcare provider about your results and any treatment decisions.

Frequently asked questions

What is a good TC/HDL ratio?

A good TC/HDL ratio is below 3.5. This means your risk for heart disease is low. A ratio between 3.5 and 5.0 is moderate risk. A ratio above 5.0 is high risk. The lower the number, the better your heart health.

Can I use this calculator if I only have 3 cholesterol numbers?

Yes. You only need 3 of the 4 values (total cholesterol, HDL, LDL, and triglycerides). Leave one field blank, and the calculator will find the missing number using the Friedewald formula. It will show an italic note under the field it filled in for you.

What does the inconsistency warning mean?

If you enter all 4 values and they don't match the Friedewald formula (TC = HDL + LDL + TG/5), a yellow warning will appear. This means your numbers may come from different tests or use a different LDL calculation method. The calculator still shows results using your entered total cholesterol.

Why does the calculator ask for my biological sex?

HDL cholesterol has different healthy ranges for men and women. For men, HDL below 40 mg/dL is considered low. For women, HDL below 50 mg/dL is considered low. Choosing your sex helps the calculator classify your HDL correctly.

What is non-HDL cholesterol?

Non-HDL cholesterol is your total cholesterol minus your HDL. It adds up all the bad types of cholesterol (LDL, VLDL, and others) into one number. A non-HDL level below 130 mg/dL is desirable. Many doctors consider it a better predictor of heart risk than LDL alone.

What is VLDL and how is it calculated?

VLDL stands for very low-density lipoprotein. It carries triglycerides through your blood and is considered a bad type of cholesterol. This calculator estimates VLDL by dividing your triglycerides by 5. This estimate works best when triglycerides are below 400 mg/dL.

How do I switch between mg/dL and mmol/L?

Click the mg/dL or mmol/L button at the top of the calculator. All your entered values will convert automatically. Make sure to pick the unit that matches your lab report before entering numbers.

Why is my TG/HDL ratio important?

The TG/HDL ratio is a strong marker for insulin resistance and small, dense LDL particles, which are the most harmful type. A TG/HDL ratio below 2.0 suggests your body handles insulin well and your LDL particles are likely large and less dangerous. A ratio above 4.0 is a warning sign.

How often should I check my cholesterol?

Most adults should get a cholesterol test every 4 to 6 years. If you have heart disease risk factors like high blood pressure, diabetes, smoking, or a family history of heart problems, your doctor may want you to test more often. Children and teens should be tested at least once between ages 9 and 11.

Do I need to fast before a cholesterol test?

Many doctors ask you to fast for 9 to 12 hours before a lipid panel. Fasting gives the most accurate triglyceride and LDL numbers. However, some newer guidelines say non-fasting tests are fine for total cholesterol and HDL. Ask your doctor which type of test you need.

What does overall risk assessment mean in the results?

The overall risk assessment combines your three ratio results (TC/HDL, LDL/HDL, and TG/HDL). If two or more are high risk, your overall risk is high. If one is high or two are moderate, your overall risk is moderate. If most are low risk, your overall risk is low.

Can cholesterol ratios be too low?

Very low cholesterol ratios usually mean your HDL is high, which is a good thing. However, extremely low total cholesterol (below 120 mg/dL) has been linked to other health concerns in some studies. If your numbers seem unusually low, talk to your doctor.

What does the Friedewald formula not work for?

The Friedewald formula becomes unreliable when triglycerides are above 400 mg/dL (4.52 mmol/L). At very high triglyceride levels, the formula underestimates LDL. In those cases, your doctor may order a direct LDL test instead.

How can I improve my cholesterol ratios?

You can improve your ratios by raising HDL and lowering LDL and triglycerides. Regular exercise, eating more fiber, reducing sugar and processed foods, quitting smoking, and losing extra weight all help. Some people also need medication like statins. Talk to your doctor about the best plan for you.

What foods raise HDL cholesterol?

Foods that help raise HDL include olive oil, fatty fish (like salmon and mackerel), nuts, avocados, whole grains, and beans. Regular exercise also raises HDL. Cutting trans fats and reducing refined carbs can help too.

Is this calculator accurate for children?

This calculator uses adult cholesterol guidelines. Children and teens have different healthy ranges. For example, a desirable total cholesterol for kids is below 170 mg/dL, not 200. If you need to check a child's cholesterol, ask your pediatrician for age-specific guidelines.

What if I select Prefer not to say for sex?

If you choose "Prefer not to say," the calculator uses the male HDL threshold of 40 mg/dL as the default low cutoff. This may slightly change how your HDL is classified. For the most accurate classification, select your biological sex if you are comfortable doing so.

Can medications affect my cholesterol ratios?

Yes. Statins lower LDL and can improve your TC/HDL and LDL/HDL ratios. Fibrates and fish oil lower triglycerides, which improves your TG/HDL ratio. Niacin can raise HDL. Always enter your most recent lab results, even if you take medication, to see your current ratios.