Calculator Inputs
Formula Used
The calculator uses the classic Friedewald style estimate.
LDL = Total Cholesterol - HDL - Estimated VLDL
Estimated VLDL = Triglycerides / Divisor
For mg/dL, the common divisor is 5. For mmol/L, the common divisor is 2.2. You can adjust the divisor when a report or clinician uses a different value.
How to Use This Calculator
- Select the same unit used on your lipid report.
- Enter total cholesterol, HDL cholesterol, and triglycerides.
- Keep the default divisor unless another divisor is required.
- Add an LDL target if you want a target gap.
- Press calculate to show results above the form.
- Use CSV or PDF buttons to save the report.
Example Data Table
| Total Cholesterol | HDL | Triglycerides | Divisor | Estimated VLDL | Estimated LDL | Category |
|---|---|---|---|---|---|---|
| 200 mg/dL | 50 mg/dL | 150 mg/dL | 5 | 30 mg/dL | 120 mg/dL | Near optimal estimate |
| 180 mg/dL | 60 mg/dL | 90 mg/dL | 5 | 18 mg/dL | 102 mg/dL | Near optimal estimate |
| 210 mg/dL | 45 mg/dL | 220 mg/dL | 5 | 44 mg/dL | 121 mg/dL | Near optimal estimate |
| 160 mg/dL | 55 mg/dL | 80 mg/dL | 5 | 16 mg/dL | 89 mg/dL | Optimal estimate |
Understanding Estimated LDL
LDL cholesterol is often called bad cholesterol because high values can support plaque buildup inside arteries. A direct lab test is useful, yet many lipid panels estimate LDL from other numbers. This calculator uses total cholesterol, HDL cholesterol, and triglycerides to estimate LDL with the Friedewald style equation. It also shows VLDL, non HDL cholesterol, common ratios, and distance from your chosen target.
Why Triglycerides Matter
Triglycerides help estimate VLDL cholesterol. In mg/dL, the usual VLDL estimate is triglycerides divided by five. In mmol/L, the common estimate is triglycerides divided by 2.2. After VLDL is estimated, it is subtracted with HDL from total cholesterol. The remaining value is the calculated LDL estimate.
When The Estimate Works Best
The classic equation works best with a fasting sample and triglycerides below 400 mg/dL, or about 4.52 mmol/L. Results may be less reliable with very high triglycerides, pregnancy, severe liver disease, kidney disease, diabetes changes, or unusual lipid disorders. Some laboratories now use newer equations or direct LDL testing for difficult samples. Treat this page as an educational estimator, not a diagnosis.
Reading The Result
Lower LDL is often preferred, but the best target depends on personal risk. A person with previous heart disease, diabetes, kidney disease, smoking history, high blood pressure, or strong family history may need a lower goal. The target gap in the result compares your calculated LDL with the target value you enter. A positive gap means the estimate is above that target. A negative gap means it is below that target.
Using The Tool Wisely
Enter values exactly as printed on your lipid report. Select the correct unit first. Keep the default divisor unless your lab or clinician uses another value. Choose the same unit for the optional target. Press calculate to see the estimate. Use the CSV file for spreadsheets. Use the PDF file for a simple record. Bring confusing results to a qualified clinician.
Important Limits
A calculated LDL value can change when the sample is not fasting. It can also change after illness, heavy meals, alcohol intake, or medicine changes. Repeat testing may be needed when numbers do not match symptoms, history, or prior reports. Never change treatment without professional medical advice.
FAQs
1. Can LDL be calculated from triglycerides alone?
No. The common estimate also needs total cholesterol and HDL cholesterol. Triglycerides are used to estimate VLDL, which is then subtracted with HDL from total cholesterol.
2. What formula does this tool use?
It uses LDL = total cholesterol - HDL - estimated VLDL. Estimated VLDL is triglycerides divided by the selected divisor.
3. What divisor should I use for mg/dL?
The common divisor for mg/dL is 5. Keep it unless your lab report, research method, or clinician recommends a different value.
4. What divisor should I use for mmol/L?
The common divisor for mmol/L is 2.2. This helps estimate VLDL when cholesterol and triglycerides are entered in mmol/L.
5. Is this result a diagnosis?
No. It is an educational estimate. Medical interpretation depends on your full history, risks, medicines, and laboratory method.
6. When is the estimate less reliable?
It is often less reliable with very high triglycerides, non-fasting samples, unusual lipid disorders, or certain medical conditions.
7. Why does the calculator show non-HDL cholesterol?
Non-HDL cholesterol equals total cholesterol minus HDL. It gives another useful lipid measure and includes several atherogenic particles.
8. Why add an LDL target?
The target lets the calculator show a gap between your estimate and goal. Your best goal should come from a clinician.