Calculate estimated LDL cholesterol or solve for total cholesterol, HDL, or triglycerides from any three lipid-panel values in mg/dL or mmol/L, with common ratios.
Estimated LDL Cholesterol Friedewald Formula
The Friedewald equation estimates LDL cholesterol from total cholesterol, HDL cholesterol, and triglycerides. This calculator uses mg/dL units.
- LDL = estimated low-density lipoprotein cholesterol, in mg/dL
- TC = total cholesterol, in mg/dL
- HDL = high-density lipoprotein cholesterol, in mg/dL
- TG = triglycerides, in mg/dL
If you leave LDL blank, the calculator applies the standard Friedewald equation above. If you leave another field blank, it rearranges the same equation:
- Calculate LDL: enter total cholesterol, HDL, and triglycerides.
- Calculate total cholesterol: enter LDL, HDL, and triglycerides.
- Calculate HDL: enter total cholesterol, LDL, and triglycerides.
- Calculate triglycerides: enter total cholesterol, HDL, and LDL.
Current LDL-C Interpretation Context
LDL-C goals are risk-specific and should be assigned from the complete clinical assessment. The former optimal, near-optimal, borderline-high, high, and very-high table was removed because it is not a one-size-fits-all 2026 treatment guide. This page demonstrates historical Friedewald arithmetic; current guidance prefers Martin/Hopkins or Sampson/NIH estimation.
When the Friedewald Estimate Is Less Reliable
| Situation | Why it matters |
|---|---|
| Triglycerides are 400 mg/dL or higher | The Friedewald equation is generally not considered valid at this level. |
| Very low LDL values | The estimate may be less accurate, especially when triglycerides are elevated. |
| Non-fasting sample | Triglycerides can be affected by recent food intake, which affects the LDL estimate. |
| Unusual lipid patterns or certain medical conditions | A direct LDL test or another estimation method may be preferred. |
Example Problems
Example 1: Calculate estimated LDL cholesterol
You have total cholesterol of 210 mg/dL, HDL of 50 mg/dL, and triglycerides of 150 mg/dL.
The estimated LDL cholesterol is 130 mg/dL.
Example 2: Calculate total cholesterol
You have LDL of 120 mg/dL, HDL of 55 mg/dL, and triglycerides of 100 mg/dL.
The calculated total cholesterol is 195 mg/dL.
FAQ
What does the Friedewald LDL calculation estimate?
It estimates LDL cholesterol using total cholesterol, HDL cholesterol, and triglycerides. The triglyceride value is divided by 5 to estimate VLDL cholesterol in mg/dL, then HDL and estimated VLDL are subtracted from total cholesterol.
Can this replace a lab result or medical advice?
No. This is a calculation based on lipid panel values. Your clinician may use additional information, such as age, blood pressure, diabetes status, smoking status, medications, and cardiovascular history, when interpreting LDL cholesterol and setting a treatment goal.
Why does the calculator require exactly three values?
The Friedewald equation has four variables: TC, HDL, TG, and LDL. If you enter any three, the missing fourth value can be found by rearranging the equation. If fewer or more than three fields are filled, there is not a single missing value to solve for.
