Free cholesterol ratio calculator
See your cholesterol ratio in two seconds. Enter your total cholesterol and HDL — and optionally triglycerides — and the calculator returns your total-cholesterol-to-HDL ratio, its category (optimal, good, borderline, or high), your non-HDL cholesterol, and the LDL/HDL ratio, with a full target-range chart — updated live, as you type.
On this page14 sections
| Total / HDL ratio | Category |
|---|---|
| Below 3.5 | Optimal |
| 3.5 – 4.5 | Good |
| 4.5 – 5.0 | Borderline |
| 5.0 and above | High |
Informational only, not a diagnosis. Limits of the cholesterol ratio
Results are estimates. Consult a professional.
What is your cholesterol ratio?
Your cholesterol ratio is your total cholesterol divided by your HDL ("good") cholesterol — a single number that captures the balance between the cholesterol that harms your arteries and the cholesterol that protects them. A standard lipid panel gives you four numbers (total, HDL, LDL, and triglycerides); the ratio condenses the two that matter most into one figure you can track over time. That is exactly what this cholesterol ratio calculator returns the moment you enter your total cholesterol and HDL.
With cholesterol, lower is better. A ratio under 3.5 is the ideal target most sources quote; risk climbs as the number approaches and passes 5, the level doctors generally want patients to stay below. A ratio of 4.0 — the US average for adults — is considered acceptable but not optimal.
How the cholesterol ratio calculator works
Read three numbers off your lab report — total cholesterol, HDL, and (optionally) triglycerides, all in mg/dL — and type them in. The calculator divides total by HDL to give your cholesterol ratio, subtracts HDL from total to give your non-HDL cholesterol, and, if you add triglycerides, estimates your LDL with the Friedewald equation and the LDL/HDL ratio alongside it.
- Enter your total cholesterol. The single all-in number at the top of your lipid panel, in mg/dL.
- Enter your HDL. Your "good" cholesterol — the higher this is, the lower (better) your ratio.
- Add your triglycerides (optional). This unlocks the Friedewald LDL estimate and the LDL/HDL ratio. Leave it blank and the LDL fields simply show a dash.
A worked example using the cholesterol ratio calculator
Sam's lipid panel comes back with a total cholesterol of 200, an HDL of 50, and triglycerides of 150 mg/dL. Here is the arithmetic the calculator runs to turn those into a ratio and the companion lipid numbers.
Step 1 — Divide total cholesterol by HDL
200 ÷ 50 = 4.00. That is the cholesterol ratio — in the "good" band (3.5–4.5), below the 5 ceiling but above the 3.5 ideal.
Step 2 — Subtract HDL to get non-HDL cholesterol
200 − 50 = 150 mg/dL of non-HDL cholesterol — every particle that isn't protective HDL, the figure many cardiologists now watch most closely.
Step 3 — Estimate LDL with Friedewald, then the LDL/HDL ratio
LDL = 200 − 50 − (150 ÷ 5) = 200 − 50 − 30 = 120 mg/dL. Then LDL ÷ HDL = 120 ÷ 50 = 2.40 — the LDL/HDL ratio.
What your cholesterol ratio number means
The ratio matters because it weighs your harmful cholesterol against your protective HDL in one figure. Two people can share the same total cholesterol of 200 yet have very different risk: one with an HDL of 40 has a ratio of 5.0 (high), while one with an HDL of 65 has a ratio of 3.1 (optimal). The total number alone misses that — the ratio captures it.
| Cholesterol ratio | Category | What it means |
|---|---|---|
| Below 3.5 | Optimal | The ideal target — lowest cardiovascular risk. |
| 3.5 – 4.5 | Good | Acceptable; below the desirable ceiling of 5. |
| 4.5 – 5.0 | Borderline | Approaching the level doctors want you under. |
| 5.0 and above | High | Higher cardiovascular risk; worth addressing. |
These are the exact bands this calculator uses to classify your ratio. Lower is better throughout. The optimal target of under 3.5 is widely cited; risk rises as the ratio nears and passes 5.
Total/HDL vs. LDL/HDL vs. non-HDL — which ratio matters?
A lipid panel supports several ratios, and they answer slightly different questions. This calculator returns all of them so you don't have to choose blind.
Which should you watch? For most people the total/HDL ratio is the quickest summary, while non-HDL cholesterol is increasingly the figure cardiologists track because it captures all the harmful particles in one number and doesn't depend on a fasting triglyceride estimate. Use the ratio to spot the balance and non-HDL to size the absolute burden.
Healthy cholesterol target ranges (mg/dL)
The ratio is most useful read alongside the raw numbers it comes from. Below are the standard US adult targets for each line on a lipid panel, so you can see where each of your inputs sits before the calculator combines them.
| Measure | Desirable | Borderline | High / at-risk |
|---|---|---|---|
| Total cholesterol | Under 200 | 200 – 239 | 240 and above |
| HDL ("good") | 60 and above | 40 – 59 | Under 40 (men) / 50 (women) |
| LDL ("bad") | Under 100 | 100 – 159 | 160 and above |
| Non-HDL cholesterol | Under 130 | 130 – 159 | 160 and above |
| Triglycerides | Under 150 | 150 – 199 | 200 and above |
| Total/HDL ratio | Under 3.5 | 3.5 – 5.0 | 5.0 and above |
Source: AHA / NCEP ATP III adult targets, in mg/dL. HDL is the one measure where higher is better. Targets are individualised — people with diabetes or known heart disease are often given tighter LDL goals.
How to improve your cholesterol ratio
Because the ratio is total over HDL, you can improve it from either side — lower the harmful cholesterol on top, or raise the protective HDL on the bottom. Raising HDL is often the more powerful lever, since it moves the denominator. The habits that do both overlap:
- Exercise regularly. Aerobic activity is one of the few reliable ways to raise HDL, and it lowers triglycerides at the same time — improving the ratio from both directions.
- Swap saturated and trans fats for unsaturated ones. Replacing butter and processed foods with olive oil, nuts, avocado, and oily fish lowers LDL while nudging HDL up.
- Add soluble fibre. Oats, beans, lentils, and fruit bind cholesterol in the gut and lower LDL, pulling the top number down.
- Lose excess weight and stop smoking. Both raise HDL and lower triglycerides; quitting smoking alone can lift HDL meaningfully within weeks.
- Discuss medication if needed. If lifestyle changes aren't enough, statins and other drugs lower LDL substantially — your clinician weighs your ratio alongside your overall risk.
Re-test on the schedule your clinician sets — usually every few years for healthy adults, more often if you're managing a risk factor — and watch the trend. Pair this calculator with the BMI calculator and the blood pressure calculator to track the other big cardiovascular numbers alongside it.
Limits of the cholesterol ratio
The ratio is a useful summary, but it is one input into cardiovascular risk, not the whole picture — and the LDL figure it relies on has known caveats.
Friedewald LDL is an estimate, not a measurement
The calculator estimates LDL with the Friedewald equation (LDL = total − HDL − triglycerides ÷ 5). That estimate becomes unreliable when triglycerides are 400 mg/dL or higher, so above that level the calculated LDL and LDL/HDL ratio are left blank — a direct LDL test is needed. The estimate is also less accurate at very low LDL levels.
Fasting and day-to-day variation
Triglycerides in particular swing with recent meals, so a non-fasting sample can throw off the Friedewald LDL. Lipid numbers also vary between blood draws — read the trend across several panels rather than reacting to a single result.
The ratio doesn't replace a full risk assessment
Your overall cardiovascular risk depends on age, blood pressure, smoking, diabetes, family history, and more — not the lipid ratio alone. Clinicians use a pooled risk estimate (such as the ASCVD risk score) that folds the ratio in with everything else. Treat this number as a tracking tool and a conversation starter, not a verdict.
Data sources and methodology
The cholesterol ratio is total cholesterol divided by HDL; non-HDL cholesterol is total minus HDL; and LDL is estimated with the Friedewald equation (Friedewald, Levy & Fredrickson, Clinical Chemistry, 1972), valid only when triglycerides are below 400 mg/dL. Target ranges and category bands follow the American Heart Association and the NCEP Adult Treatment Panel guidance, in mg/dL (the US unit; this tool is mg/dL only). All values are computed from your inputs and rounded for display.
American Heart Association — cholesterol levels, HDL/LDL, and the total-cholesterol-to-HDL ratio.Friedewald WT, Levy RI, Fredrickson DS — estimation of LDL cholesterol without the use of the preparative ultracentrifuge (Clinical Chemistry, 1972).Frequently asked questions about the free cholesterol ratio calculator
About this cholesterol ratio calculator
This cholesterol ratio calculator runs entirely in your browser. The values you type never leave your device — nothing is sent to a server, logged, or shared. It divides total cholesterol by HDL for your ratio, classifies it against the standard bands, and estimates non-HDL, LDL (Friedewald), and the LDL/HDL ratio, updating instantly on every change.
Calculators Cloud offers 400+ free tools with no sign-up. The whole Health calculators shelf includes BMI, blood pressure, and A1c tools alongside this one. Or browse the full calculator directory.