BYTETOOLS

Cholesterol Ratio Calculator

Calculate total:HDL, LDL:HDL and triglyceride:HDL ratios plus non-HDL cholesterol and Friedewald LDL, in mg/dL or mmol/L, against standard reference bands.

Total cholesterol to HDL ratio

4.0 : 1

200 mg/dL total ÷ 50 mg/dL HDL. Below 5 is the usual target and below 3.5 is often described as optimal.

4.0
Total : HDL
2.4
LDL : HDL
3.0
Triglyceride : HDL
150 mg/dL
Non-HDL cholesterol

Every figure against its reference band

MeasureYour valueCommon targetBand
Total cholesterol200 mg/dLBelow 200 mg/dL (5.2 mmol/L)Borderline
LDL cholesterol (Friedewald)120 mg/dLBelow 100 mg/dL (2.6 mmol/L)Borderline
HDL cholesterol50 mg/dLAbove 40 mg/dL (1.0 mmol/L)Borderline
Triglycerides150 mg/dLBelow 150 mg/dL (1.7 mmol/L)Borderline
Non-HDL cholesterol150 mg/dLBelow 130 mg/dL (3.4 mmol/L)Borderline
Total : HDL ratio4.00Below 5, ideally below 3.5Borderline
LDL : HDL ratio2.40Below 2, concerning above 3.5Borderline
Triglyceride : HDL ratio (mg/dL)3.00Below 2, concerning above 4Borderline

Friedewald (1972): LDL = total cholesterol − HDL − triglycerides ÷ 5 in mg/dL, or ÷ 2.2 in mmol/L. Worked example: 200 − 50 − 150 ÷ 5 = 120 mg/dL. Unit conversions use 38.67 mg/dL per mmol/L for cholesterol and 88.57 for triglycerides. The triglyceride:HDL ratio is always shown on the mg/dL scale, because the two analytes have different molar masses and the published thresholds only exist in those units.

Not a diagnosis and not medical advice — this is arithmetic on numbers you typed. Lipid ratios are only one input into cardiovascular risk; a proper assessment uses a validated calculator such as QRISK3, ASCVD or SCORE2, which also weigh age, blood pressure, smoking, diabetes, family history and ethnicity. The reference bands here follow common US and UK guidance and are not universal — targets are much tighter if you already have cardiovascular disease or familial hypercholesterolaemia. Take your actual lab report to your doctor.

What is the Cholesterol Ratio Calculator?

The total cholesterol to HDL ratio is total cholesterol divided by HDL. Below 5 is the usual target and below 3.5 is often described as optimal. LDL can be estimated with the Friedewald equation: LDL = total − HDL − triglycerides ÷ 5 in mg/dL.

  • Total:HDL, LDL:HDL and triglyceride:HDL ratios plus non-HDL cholesterol
  • Friedewald LDL estimate, correctly withheld above 400 mg/dL of triglycerides
  • Directly measured LDL supported as an alternative to the estimate
  • mg/dL and mmol/L with automatic conversion when you switch units
  • Sex-specific HDL target band and a colour-coded reference table
  • Fully local in your browser — your lab results are never uploaded

How to use the Cholesterol Ratio Calculator

  1. 1

    Choose mg/dL or mmol/L to match your lab report, and select your sex to set the right HDL target band.

  2. 2

    Enter total cholesterol, HDL and triglycerides from the panel.

  3. 3

    Leave LDL set to the Friedewald estimate, or switch to a directly measured LDL and type it in.

  4. 4

    Read the total:HDL ratio headline and the four summary tiles for the other ratios and non-HDL cholesterol.

  5. 5

    Check the reference table to see every figure and ratio against its common target band.

About the Cholesterol Ratio Calculator

The ByteTools Cholesterol Ratio Calculator takes the three figures every lipid panel reports — total cholesterol, HDL and triglycerides — and produces the ratios that get quoted in guidelines and consultations. It gives total:HDL, LDL:HDL and triglyceride:HDL, plus non-HDL cholesterol, and estimates LDL with the Friedewald equation when you do not have a directly measured value.

It is honest about where Friedewald stops working. Above 400 mg/dL (4.5 mmol/L) of triglycerides the equation's assumption that VLDL cholesterol is one fifth of triglycerides breaks down, so the LDL figures are withheld rather than quietly reported wrong. Non-HDL cholesterol stays valid at any triglyceride level and is shown alongside.

Both mg/dL and mmol/L are supported and your numbers are converted when you switch. Everything is computed in your browser and nothing is uploaded. This is not a diagnosis and not medical advice — ratios are one input into cardiovascular risk, and a proper assessment uses a validated tool like QRISK3, ASCVD or SCORE2. Take your actual lab report to your doctor.

Frequently asked questions

What is a good cholesterol ratio?

For total cholesterol to HDL, below 5 is the usual target and below 3.5 is often described as optimal. LDL:HDL is generally considered good below 2 and concerning above about 3.5, and triglyceride:HDL on the mg/dL scale is best below 2. Individual targets are tighter if you already have cardiovascular disease.

How do you calculate LDL cholesterol without a direct test?

The Friedewald equation: LDL = total cholesterol − HDL − triglycerides ÷ 5 when everything is in mg/dL, or ÷ 2.2 in mmol/L. With a total of 200, HDL of 50 and triglycerides of 150 mg/dL, LDL comes out at 120 mg/dL.

Why does the Friedewald equation fail at high triglycerides?

It assumes VLDL cholesterol is exactly one fifth of triglycerides, which holds reasonably in a fasting sample with normal levels. Above 400 mg/dL (4.5 mmol/L) that ratio no longer applies and the calculated LDL becomes unreliable, so this tool withholds it and points you to non-HDL cholesterol or a direct LDL measurement instead.

What is non-HDL cholesterol and why does it matter?

It is simply total cholesterol minus HDL, which captures every atherogenic particle in one number. It needs no fasting sample, stays valid at any triglyceride level, and many guidelines now treat it as at least as useful as LDL. Below 130 mg/dL (3.4 mmol/L) is a common target.

Is the triglyceride to HDL ratio the same in mmol/L?

No, and this trips people up. Triglycerides and cholesterol have very different molar masses, so the ratio changes value when you switch units. The published thresholds only exist on the mg/dL scale, which is why this calculator always reports that ratio in mg/dL and labels it accordingly.

Are my lab results sent anywhere?

No. All the arithmetic happens in JavaScript inside your browser. Your cholesterol figures are never uploaded, logged or stored, and the page works with no network connection.

Related tools