Calculator
Formula Used
Friedewald in mg/dL: LDL = Total cholesterol - HDL - (Triglycerides / 5).
Friedewald in mmol/L: LDL = Total cholesterol - HDL - (Triglycerides / 2.2).
Direct VLDL method: LDL = Total cholesterol - HDL - VLDL.
Non-HDL cholesterol: Non-HDL = Total cholesterol - HDL.
Total cholesterol and HDL alone show non-HDL cholesterol. LDL needs triglycerides or VLDL for separation.
How To Use This Calculator
- Choose the unit printed on your lipid report.
- Enter total cholesterol and HDL cholesterol.
- Enter triglycerides for the Friedewald method.
- Use known VLDL only when your report gives it.
- Add your target LDL and sample note.
- Press Calculate to show results above the form.
- Use CSV or PDF buttons to save the report.
Example Data Table
| Total Cholesterol | HDL | Triglycerides | Estimated VLDL | Calculated LDL | Non-HDL |
|---|---|---|---|---|---|
| 200 mg/dL | 50 mg/dL | 150 mg/dL | 30 mg/dL | 120 mg/dL | 150 mg/dL |
| 5.20 mmol/L | 1.30 mmol/L | 1.70 mmol/L | 0.77 mmol/L | 3.13 mmol/L | 3.90 mmol/L |
| 180 mg/dL | 60 mg/dL | 100 mg/dL | 20 mg/dL | 100 mg/dL | 120 mg/dL |
Understanding LDL From Common Lipid Values
Low density lipoprotein is often called LDL cholesterol. Many reports show total cholesterol and HDL cholesterol first. People then want the missing LDL value. This calculator helps by using the common lipid relationship. It also shows non-HDL cholesterol, cholesterol ratio, VLDL estimate, and risk notes.
Why LDL Estimation Matters
LDL carries cholesterol particles from the liver to body tissues. A high calculated value can suggest more plaque forming potential. HDL works differently. It helps move cholesterol away from arteries. Total cholesterol is the combined amount of several cholesterol fractions. Because of that, LDL cannot be found from total and HDL alone with high certainty. The missing part is usually VLDL. VLDL is commonly estimated from triglycerides.
What This Tool Calculates
The Friedewald equation is widely used for fasting lipid panels. It estimates LDL by subtracting HDL and VLDL from total cholesterol. In mg/dL, VLDL is estimated as triglycerides divided by five. In mmol/L, VLDL is estimated as triglycerides divided by 2.2. The calculator also accepts a direct VLDL value. This is useful when a lab provides VLDL separately.
The tool supports common units and multiple calculation modes. It can estimate LDL, show non-HDL cholesterol, and compare the output with broad adult categories. It also calculates total to HDL ratio. This ratio gives another quick view of lipid balance. Results can be saved as CSV or PDF for records, lessons, or repeat checks.
Using Results Safely
Use clean data for better output. Enter values exactly as shown on a recent lipid report. Select the same unit for all cholesterol values. If using the Friedewald method, include triglycerides. Avoid using the formula when triglycerides are very high. In that case, a direct LDL test may be better.
This calculator is an educational aid. It does not diagnose disease. Lipid goals depend on age, history, medicines, diabetes, blood pressure, and smoking status. A clinician can explain target ranges and treatment options. Use the result to prepare better questions and track patterns over time.
Keep the same testing state when comparing records. Fasting and nonfasting panels can differ. Recent meals may raise triglycerides. Weight change, illness, and medicines can also shift values. Record dates and notes beside each result. Trends are often more useful than one isolated reading for personal planning over several months.
FAQs
Can LDL be calculated from total and HDL only?
Not exactly. Total cholesterol and HDL can show non-HDL cholesterol. LDL needs triglycerides or VLDL because total cholesterol includes more than LDL and HDL.
Which formula does this calculator use?
The default method is Friedewald. It subtracts HDL and estimated VLDL from total cholesterol. VLDL is estimated from triglycerides.
Why do I need triglycerides?
Triglycerides help estimate VLDL. After VLDL is estimated, LDL can be separated from the total cholesterol value.
Can I use mmol/L values?
Yes. Select mmol/L before entering values. The calculator uses the correct Friedewald divisor for that unit.
When is Friedewald LDL less reliable?
It can be less reliable when triglycerides are very high. It may also be less reliable when the sample is not fasting.
Is non-HDL cholesterol the same as LDL?
No. Non-HDL includes LDL and other atherogenic particles. It is useful, but it is not the same as LDL.
Can I download my result?
Yes. Submit the form with the CSV or PDF button. The file includes inputs, method, formula, and results.
Does this calculator give medical advice?
No. It is for education and record keeping. Ask a qualified clinician about targets, medicines, and personal risk.