What is a cholesterol calculator?

A cholesterol calculator analyzes your lipid panel — total cholesterol, HDL, LDL, and triglycerides — and computes derived values like non-HDL cholesterol and the total/HDL ratio. It classifies each component against NCEP ATP III categories so you can understand what your numbers mean.

How is LDL calculated using the Friedewald equation?

Friedewald equation: LDL = Total Cholesterol − HDL − (Triglycerides / 5). It assumes VLDL = Triglycerides/5, which is reliable when triglycerides are under 400 mg/dL. Above that, the equation breaks down and LDL must be measured directly.

What are normal cholesterol levels?

Total cholesterol under 200, LDL under 100, HDL above 40 (men) or 50 (women), triglycerides under 150 mg/dL. These are the NCEP ATP III categories. Your personal target may be lower if you have other risk factors like diabetes or prior heart disease.

What is the difference between LDL and HDL?

LDL (low-density lipoprotein) carries cholesterol from the liver to body cells; high LDL deposits in artery walls, forming plaques. HDL (high-density lipoprotein) does the reverse — carries cholesterol from cells back to the liver for disposal. Higher HDL is protective; higher LDL is harmful.

What is non-HDL cholesterol?

Non-HDL = Total Cholesterol − HDL. It captures all the atherogenic particles (LDL plus VLDL, IDL, Lp(a), etc.) in a single number. Modern guidelines often prefer non-HDL over LDL because it remains accurate when triglycerides are high and is a stronger predictor of cardiovascular events.

What is the total cholesterol to HDL ratio?

Total/HDL ratio is total cholesterol divided by HDL. Under 3.5 is desirable; under 5 is acceptable; above 5 indicates higher cardiovascular risk. It's a quick proxy for cardiovascular risk that captures both your atherogenic burden and your protective lipoproteins in one number.

Can diet really lower cholesterol?

Yes, meaningfully. A Mediterranean-style diet (olive oil, nuts, fish, vegetables, whole grains, low red meat) lowers LDL by 5-15%. Adding soluble fiber (oats, beans) can drop LDL another 5-10%. Weight loss alone drops LDL by ~5 mg/dL per 10 lb lost. Combined lifestyle changes can match a low-dose statin in many people.

Generally yes, but very high HDL (above 100 mg/dL) doesn't appear to provide additional protection and may even be associated with increased risk in some studies. The relationship is curvilinear, not linear. Most people benefit from getting HDL into the 40-60 range; pushing it higher with drugs has not been proven helpful.

Cholesterol Calculator

A lipid panel reports four numbers: total cholesterol, HDL, triglycerides, and (sometimes) LDL. Our cholesterol calculator computes LDL using the Friedewald equation if it's not directly measured, derives non-HDL cholesterol (which captures all the atherogenic particles), and calculates the total/HDL and LDL/HDL ratios. It then classifies each value against the NCEP ATP III categories — Optimal, Near Optimal, Borderline High, High — and synthesizes them into an overall risk picture. Use it to understand a lab report, track changes over time, and see how each component contributes to your cardiovascular risk profile.

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calendar_today Updated: April 2026

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science Lipid Panel (mg/dL)

Total Cholesterol

HDL

LDL (optional)

Leave 0 to compute via Friedewald

Triglycerides

analytics Lipid Analysis

Overall Risk

Moderate Risk

Total 210 · Borderline High

LDL 130 · Borderline High

HDL 50 · Average

Triglycerides 150 · Borderline High

Non-HDL

160

TC/HDL

4.20

LDL/HDL

2.60

Interpretation

Multiple lipid abnormalities — consider lifestyle changes and discuss with doctor

tips_and_updates Tips

• Total cholesterol: <200 desirable, 200-239 borderline, ≥240 high
• LDL: <100 optimal, 100-129 near optimal, 130-159 borderline, 160-189 high, ≥190 very high
• HDL: <40 low (risk factor), 40-59 average, ≥60 protective
• Triglycerides: <150 normal, 150-199 borderline, 200-499 high, ≥500 very high
• Non-HDL = total − HDL is more reliable than LDL when triglycerides are elevated
• Total/HDL ratio under 3.5 is desirable; under 5 is acceptable
• Lifestyle (Mediterranean diet, exercise, weight loss) can drop LDL by 20-30%

functions Formula

{LDL (Friedewald) = Total − HDL − Triglycerides/5 (valid if TG < 400) [{Total Cholesterol Sum of all cholesterol particles} {HDL High-density lipoprotein — protective ('good')} {LDL Low-density lipoprotein — atherogenic ('bad')} {Triglycerides Fat circulating in blood, often diet-related} {Non-HDL Total − HDL = sum of all atherogenic particles} {Total/HDL Ratio Lower is better; <3.5 desirable} {LDL/HDL Ratio Lower is better; <2.5 desirable}] The Friedewald equation estimates LDL when it's not directly measured. It assumes triglycerides and VLDL are in a fixed ratio, which breaks down when triglycerides exceed 400 mg/dL. Non-HDL cholesterol is increasingly used because it captures all atherogenic lipoproteins (LDL + VLDL + IDL + Lp(a)) and is reliable even with high triglycerides. NCEP ATP III categories are the standard framework for interpreting lipid values.}

science Example: Borderline lipid panel

LDL via Friedewald = 210 − 50 − 150/5 = 130 mg/dL. Non-HDL = 210 − 50 = 160. Total/HDL ratio = 4.2 (above the desirable 3.5). All values are borderline high — none catastrophic individually, but combined they put this person in a moderate-risk category. Lifestyle changes (diet, exercise) should be the first intervention.

Expected Results

Overall Risk Moderate Risk

LDL 130

Non-HDL Cholesterol 160

Total/HDL Ratio 4.2

LDL/HDL Ratio 2.6

Total Category Borderline High

LDL Category Borderline High

HDL Category Average

Triglycerides Category Borderline High

How to Use This Calculator

Enter total cholesterol

Input total cholesterol from your lab report.

Enter HDL

Provide HDL (high-density lipoprotein).

Enter LDL or leave blank

Input LDL if measured, or leave 0 to calculate via Friedewald.

Enter triglycerides

Provide triglycerides.

Read interpretation

Review LDL, non-HDL, ratios, and category for each value.

The Formula

The Friedewald equation estimates LDL when it's not directly measured. It assumes triglycerides and VLDL are in a fixed ratio, which breaks down when triglycerides exceed 400 mg/dL. Non-HDL cholesterol is increasingly used because it captures all atherogenic lipoproteins (LDL + VLDL + IDL + Lp(a)) and is reliable even with high triglycerides. NCEP ATP III categories are the standard framework for interpreting lipid values.

LDL (Friedewald) = Total − HDL − Triglycerides/5 (valid if TG < 400)

lightbulb Variables Explained

Total Cholesterol Sum of all cholesterol particles
HDL High-density lipoprotein — protective ('good')
LDL Low-density lipoprotein — atherogenic ('bad')
Triglycerides Fat circulating in blood, often diet-related
Non-HDL Total − HDL = sum of all atherogenic particles
Total/HDL Ratio Lower is better; <3.5 desirable
LDL/HDL Ratio Lower is better; <2.5 desirable

tips_and_updates Pro Tips

Total cholesterol: <200 desirable, 200-239 borderline, ≥240 high

LDL: <100 optimal, 100-129 near optimal, 130-159 borderline, 160-189 high, ≥190 very high

HDL: <40 low (risk factor), 40-59 average, ≥60 protective

Triglycerides: <150 normal, 150-199 borderline, 200-499 high, ≥500 very high

Non-HDL = total − HDL is more reliable than LDL when triglycerides are elevated

Total/HDL ratio under 3.5 is desirable; under 5 is acceptable

Lifestyle (Mediterranean diet, exercise, weight loss) can drop LDL by 20-30%

A 'good' cholesterol report needs all four metrics in healthy ranges, not just total cholesterol. Two people can have identical total cholesterol of 200 but very different cardiovascular risk depending on their HDL and triglycerides. High HDL with moderate LDL is much safer than low HDL with the same LDL. Modern guidelines emphasize the full panel and derived metrics like non-HDL and the total/HDL ratio over total cholesterol alone.

The Friedewald equation assumes a fixed ratio of triglycerides to VLDL cholesterol. This works well when triglycerides are below 400 mg/dL, which covers the vast majority of patients. Above 400, the equation overestimates VLDL and underestimates LDL. In those cases, labs use direct LDL measurement or non-HDL cholesterol as the primary metric. If your triglycerides are above 400, prefer the directly measured LDL or non-HDL value.

Frequently Asked Questions

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