Health calculators

HDL Calculator

Updated Sep 21, 2026 By Infinity Calculator
Rate Formulas Medical disclaimer
Required. HDL is needed for every ratio below. LDL is optional — leave it blank and it will be estimated with the Friedewald equation.
Lipid Panel
Units for results (also switches every input below)
All cholesterol carried in your blood.
The "good" cholesterol that clears lipids from arteries.
Blank = estimated from the other three values.
Fasting value gives the most reliable ratios.
Risk Profile (for the 10-Year ASCVD Score)
Years. Risk scoring applies to ages 40–79.
Biological Sex
Sets the low-HDL threshold (40 vs 50 mg/dL).
The Pooled Cohort Equations use separate coefficients.
Current Smoker
Diagnosed Diabetes
The top number of your reading.
On Blood-Pressure Medication

Your Results

HDL Cholesterol
—
Total Cholesterol ÷ HDL
—
LDL ÷ HDL
—
Triglycerides ÷ HDL
—
LDL Cholesterol
—
Non-HDL Cholesterol
—
VLDL (estimated)
—
Cardiovascular "Heart Age"
—
—
10-Year ASCVD Risk (Pooled Cohort Equations)
—
Your Lipid Panel vs. Target Ranges
Measure Your Value Target Status
Lipid Levels vs. Targets
Your Ratios vs. Optimal Thresholds
Step-by-Step Solution
What Your Numbers Point To

    Introduction

    HDL is the "good" cholesterol. It picks up extra fat from your blood vessels and carries it to your liver, where your body gets rid of it. A higher HDL number usually means better heart health.

    This HDL calculator takes the numbers from your lipid blood test and shows what they mean. It works in mg/dL (US) or mmol/L (SI), and you can switch units at any time. If you don't know your LDL, leave it blank and the tool estimates it with the Friedewald equation.

    The results show:

    • Your HDL level: low, borderline, or protective, based on your sex.
    • Three cholesterol ratios: total cholesterol ÷ HDL, LDL ÷ HDL, and triglycerides ÷ HDL.
    • Non-HDL and VLDL cholesterol: the "bad" particles added up.
    • Your 10-year ASCVD risk: the chance of a heart attack or stroke, using the Pooled Cohort Equations for ages 40 to 79.
    • Your heart age: how old your heart acts compared to your real age.

    You also see step-by-step math, charts, and a table that compares each value to its target. Use it to track progress, but talk to your doctor before changing any treatment.

    How to use our HDL Calculator

    Enter your lipid panel numbers and a few health details. The calculator shows your HDL level, your cholesterol ratios (total-to-HDL, LDL-to-HDL, and triglyceride-to-HDL), your non-HDL and VLDL levels, your 10-year heart risk score, and your heart age.

    Units for results: Pick mg/dL if your lab report is from the US, or mmol/L if it uses SI units. This switches every lipid box at once.

    Total Cholesterol: Type the total cholesterol number from your blood test. This is all the cholesterol in your blood.

    HDL Cholesterol: Type your HDL, the "good" cholesterol. This is required, since every ratio divides by it.

    LDL Cholesterol: Type your LDL if your lab lists it. You can leave it blank and the tool will estimate it with the Friedewald equation.

    Triglycerides: Type your triglyceride level. A fasting test gives the most accurate ratios.

    Age: Enter your age in years. The 10-year risk score only works for ages 40 to 79.

    Biological Sex: Choose male or female. This sets the low-HDL cutoff, which is 40 mg/dL for men and 50 mg/dL for women.

    Race / Ethnicity: Choose African American or White/other. The risk formula uses different numbers for each group.

    Current Smoker: Pick Yes if you smoke now. Smoking raises your heart risk score.

    Diagnosed Diabetes: Pick Yes if a doctor has told you that you have diabetes.

    Systolic Blood Pressure: Enter the top number of your blood pressure reading in mmHg or kPa.

    On Blood-Pressure Medication: Pick Yes if you take pills to lower your blood pressure.

    Press Calculate to see your results, charts, and step-by-step math. Press Reset to start over with the sample values.

    What Is HDL Cholesterol?

    HDL stands for high-density lipoprotein. People call it the "good" cholesterol. HDL acts like a truck in your blood. It picks up extra cholesterol from your artery walls and carries it back to your liver, where your body gets rid of it. The more HDL you have, the cleaner your arteries tend to stay.

    LDL, the "bad" cholesterol, does the opposite. It drops cholesterol off in your artery walls. Over the years that buildup, called plaque, makes arteries narrow and stiff. That is how heart attacks and strokes start.

    What Counts as a Good HDL Level?

    • Low (risky): under 40 mg/dL for men, under 50 mg/dL for women
    • Okay: 40 to 59 mg/dL
    • Protective: 60 mg/dL or higher

    In SI units, 60 mg/dL is about 1.55 mmol/L. Low HDL counts as its own heart disease risk factor, even when your other numbers look fine.

    Why Cholesterol Ratios Matter

    One number alone does not tell the whole story. Ratios compare the harmful cholesterol to the helpful kind, so they often predict heart risk better than a single value.

    • Total Cholesterol ÷ HDL: Under 3.5 is great. Over 5 raises concern. This shows how much of your cholesterol is not the protective kind.
    • LDL ÷ HDL: Under 2.0 is best. This weighs artery-clogging LDL against artery-cleaning HDL.
    • Triglycerides ÷ HDL: Under 2.0 is ideal. A number above 4 is often a warning sign of insulin resistance, which is linked to type 2 diabetes.

    Other Numbers on Your Lipid Panel

    Non-HDL cholesterol is your total minus your HDL. It adds up every particle that can clog arteries. Aim for under 130 mg/dL, or under 100 mg/dL if you have diabetes.

    VLDL carries triglycerides. Labs usually estimate it as triglycerides divided by 5. Normal is about 2 to 30 mg/dL.

    LDL is often estimated with the Friedewald equation: Total − HDL − (Triglycerides ÷ 5). This estimate stops working well when triglycerides go above 400 mg/dL. In that case, ask your lab for a direct LDL measurement.

    10-Year ASCVD Risk and Heart Age

    The Pooled Cohort Equations use your age, sex, race, cholesterol, blood pressure, smoking, and diabetes status to estimate your chance of a heart attack or stroke in the next 10 years. The score applies to adults aged 40 to 79.

    • Under 5%: low risk
    • 5% to 7.4%: borderline
    • 7.5% to 19.9%: intermediate
    • 20% or more: high risk

    "Heart age" turns that score into a simpler idea. If your heart age is higher than your real age, your arteries are aging faster than the rest of you.

    How to Raise HDL and Lower Risk

    • Move more. About 30 minutes of brisk walking, biking, or swimming most days can lift HDL by 5% to 10%.
    • Quit smoking. HDL often climbs within weeks of stopping.
    • Pick better fats. Olive oil, nuts, avocado, and fatty fish help. Fried food and trans fats hurt.
    • Cut sugar and refined carbs. This is the fastest way to drop triglycerides, which pushes your TG/HDL ratio down.
    • Lose extra weight. Dropping even 5% to 10% of body weight improves most lipid numbers.
    • Go easy on alcohol. Heavy drinking raises triglycerides sharply.

    Getting an Accurate Test

    For the most reliable triglycerides and LDL estimate, fast 9 to 12 hours before your blood draw. Water is fine. Sickness, recent surgery, pregnancy, and some medicines can shift results, so re-test later if any of those apply.

    These numbers are a snapshot, not a diagnosis. Share your results with a doctor, who will look at your full history before suggesting any treatment.

    Formulas used

    Unit conversion (cholesterol and triglycerides, mmol/L to mg/dL)
    \text{Chol}_{mg/dL} = \text{Chol}_{mmol/L} \times 38.67 \qquad \text{TG}_{mg/dL} = \text{TG}_{mmol/L} \times 88.57
    Non-HDL cholesterol
    \text{Non-HDL} = \text{TC} - \text{HDL}
    Estimated VLDL cholesterol
    \text{VLDL} = \frac{\text{TG}}{5}
    LDL cholesterol (Friedewald estimate, valid for TG \le 400 mg/dL)
    \text{LDL} = \text{TC} - \text{HDL} - \frac{\text{TG}}{5}
    Cholesterol ratios
    R_{TC/HDL} = \frac{\text{TC}}{\text{HDL}}, \qquad R_{LDL/HDL} = \frac{\text{LDL}}{\text{HDL}}, \qquad R_{TG/HDL} = \frac{\text{TG}}{\text{HDL}}
    10-year ASCVD risk (Pooled Cohort Equations)
    \text{Risk}_{10} = \left(1 - S_0^{\,\exp\left(\sum_i \beta_i x_i - \overline{\text{LP}}\right)}\right) \times 100\%
    Pooled Cohort linear predictor (white male example)
    \sum_i \beta_i x_i = 12.344\ln(\text{Age}) + 11.853\ln(\text{TC}) - 2.664\ln(\text{Age})\ln(\text{TC}) - 7.990\ln(\text{HDL}) + 1.769\ln(\text{Age})\ln(\text{HDL}) + \beta_{SBP}\ln(\text{SBP}) + 7.837\,S - 1.795\ln(\text{Age})\,S + 0.658\,D
    Cardiovascular heart age
    \text{HeartAge} = a \;\text{ such that }\; \text{Risk}_{10}(a,\ \text{TC}=170,\ \text{HDL}=50,\ \text{SBP}=110,\ S=0,\ D=0) = \text{Risk}_{10}

    Frequently asked questions

    Can HDL cholesterol be too high?

    Yes. Once HDL passes about 90 mg/dL (2.3 mmol/L), the extra protection stops. Very high HDL, above roughly 100 mg/dL, has been linked to more heart problems and deaths, not fewer.

    Very high HDL is often caused by genes, heavy alcohol use, or some medicines. If your HDL is unusually high, ask your doctor why instead of treating it as a win.

    What causes low HDL cholesterol?

    Common causes include:

    • Smoking
    • Extra belly fat and little exercise
    • Type 2 diabetes or insulin resistance
    • High triglycerides
    • Very low-fat, high-sugar diets
    • Family genes you cannot change
    • Some drugs, such as anabolic steroids, beta blockers, and progestins

    Many people with low HDL have more than one cause at the same time.

    How long does it take to raise HDL cholesterol?

    Plan on about 8 to 12 weeks. Exercise, weight loss, and diet changes need that long to show up in a blood test.

    Quitting smoking works faster. HDL often starts climbing within 2 to 3 weeks and can gain 5 to 10 percent in a few months.

    Most doctors retest lipids about 3 months after you make a change.

    Do statins raise HDL cholesterol?

    A little. Statins usually lift HDL by about 5 to 10 percent. Their real job is cutting LDL, and that is where the heart benefit comes from.

    Niacin and fibrates raise HDL more, but adding them on top of a statin did not prevent heart attacks in trials. That is why no drug is prescribed just to push HDL up.

    Can you still have a heart attack with high HDL?

    Yes. High HDL does not cancel out high LDL, high blood pressure, smoking, or diabetes.

    HDL also has to work well, not just be present. Some people have plenty of HDL particles that do a poor job of clearing cholesterol from arteries. Treat a high HDL as a bonus, not as permission to ignore your other numbers.

    Why is my HDL low when my triglycerides are high?

    These two numbers move in opposite directions. When triglycerides rise, fat gets swapped into HDL particles. Those changed particles break down and leave your blood faster, so your HDL reading drops.

    The fix is usually the same for both: cut sugar and refined carbs, drink less alcohol, move more, and lose extra weight. Lower triglycerides almost always pull HDL back up.

    Does menopause lower HDL cholesterol?

    Estrogen helps keep HDL up, so when it falls at menopause HDL can slip a few points. The bigger changes are a rise in LDL and triglycerides, which often jump 10 to 15 percent over the transition.

    Many women see their cholesterol ratio get worse in their 50s even with no change in diet. Regular testing during those years is smart.

    Does drinking alcohol raise HDL?

    One drink a day can raise HDL by a few points. But that does not make drinking good for your heart.

    Alcohol also raises triglycerides, blood pressure, and cancer risk, and heavy drinking wrecks lipid numbers. No health group tells people to start drinking for HDL. Exercise raises HDL just as well with no downside.

    Is an HDL of 35 bad?

    Yes, 35 mg/dL (about 0.9 mmol/L) is low for both men and women. The cutoffs are 40 mg/dL for men and 50 mg/dL for women.

    Low HDL counts as its own heart disease risk factor, even if your total cholesterol looks fine. It also raises your total-to-HDL ratio, which is one of the strongest warning signs on a lipid panel.

    Do you have to fast before an HDL test?

    Not for HDL itself. HDL and total cholesterol barely move after a meal, so a non-fasting test gives a fine HDL number.

    Fasting 9 to 12 hours matters for triglycerides, which spike after eating. Since the LDL estimate and the TG/HDL ratio both depend on triglycerides, a fasting draw gives the most useful full panel.

    Does low HDL cause any symptoms?

    No. Low HDL causes no pain, no tiredness, and no warning signs at all. The only way to find it is a blood test.

    Damage builds quietly in the artery walls for years. The first symptom for many people is chest pain, a heart attack, or a stroke, which is why routine testing matters.

    How often should adults get a cholesterol test?

    Healthy adults over 20 should test every 4 to 6 years. Test more often if you:

    • Have diabetes, high blood pressure, or heart disease
    • Smoke or carry extra weight
    • Have a family history of early heart disease
    • Take cholesterol medicine
    • Had an abnormal result last time

    Kids should be checked once between ages 9 and 11, and again between 17 and 21.

    Does fish oil raise HDL cholesterol?

    Only a little. Omega-3 fats from fish oil can nudge HDL up a few percent. What they really do is cut triglycerides, often by 20 to 30 percent at prescription doses.

    Because lower triglycerides improve your TG/HDL ratio, fish oil can still help the overall picture. Eating fatty fish like salmon or sardines twice a week is the simplest way to get it.

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