# LDL Cholesterol Calculator (Friedewald)

URL: https://speedycalculator.com/calculators/health/ldl-cholesterol/
Last updated: 2026-10-25

> The LDL calculator estimates LDL (“bad”) cholesterol from total cholesterol, HDL and triglycerides using the Friedewald equation. It also shows non-HDL cholesterol and the total-to-HDL ratio.

## Inputs

- Total cholesterol (mg/dL, mmol/L)
- HDL cholesterol (mg/dL, mmol/L)
- Triglycerides (mg/dL, mmol/L)

## Results

- LDL cholesterol
- Non-HDL cholesterol
- Total / HDL ratio

## Formula

```
LDL = total cholesterol − HDL − triglycerides ÷ 5   (mg/dL)
```

## Explanation

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

FieldWhat to enterTotal cholesterolUnits: mg/dL, mmol/LHDL cholesterolUnits: mg/dL, mmol/LTriglyceridesUnits: 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)1002015070200120250170300220400320
*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.*

## 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.

## FAQ

**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).


## Sources

- [Friedewald WT et al. Estimation of the concentration of LDL cholesterol in plasma. Clin Chem, 1972](https://pubmed.ncbi.nlm.nih.gov/4337382/)