Many labs calculate rather than measure LDL. The Friedewald equation is not valid when triglycerides exceed 400 mg/dL.
How to use the LDL Cholesterol Calculator
- Total cholesterol
- HDL cholesterol
- Triglycerides
Results update as you type, and every field accepts the units shown in its menu.
How it works
Subtract HDL and one fifth of triglycerides from total cholesterol.
Inputs explained
| Field | What to enter |
|---|---|
| Total cholesterol | Units: mg/dL, mmol/L |
| HDL cholesterol | Units: mg/dL, mmol/L |
| Triglycerides | Units: mg/dL, mmol/L |
What each result means
- Non-HDL cholesterol = [Total cholesterol] – [HDL cholesterol]
- Total / HDL ratio = [Total cholesterol] ÷ [HDL cholesterol]
Example values
How the main result changes when Total cholesterol changes and everything else stays at the example values above:
| Total cholesterol (mg/dL) | LDL cholesterol (mg/dL) |
|---|---|
| 100 | 20 |
| 150 | 70 |
| 200 | 120 |
| 250 | 170 |
| 300 | 220 |
| 400 | 320 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
LDL = total cholesterol − HDL − triglycerides ÷ 5 (mg/dL)Worked example
Inputs — Total cholesterol: 200 mg/dL; HDL cholesterol: 50 mg/dL; Triglycerides: 150 mg/dL.
Results — LDL cholesterol = 120 mg/dL; Non-HDL cholesterol = 150 mg/dL; Total / HDL ratio = 4.
Key terms
- Non-HDL cholesterol
- Total cholesterol minus HDL.
Frequently asked questions
Why is there no result?
Triglycerides of 400 mg/dL or more make the Friedewald estimate unreliable.
What is a good total/HDL ratio?
Below 5 is often quoted; below 3.5 is considered ideal.
What formula does the LDL Cholesterol Calculator use?
LDL = total cholesterol − HDL − triglycerides ÷ 5 (mg/dL).