LDL Cholesterol Calculator (Friedewald Equation)

Calculate LDL cholesterol using the Friedewald Equation. This tool is designed for health professionals to accurately assess cholesterol levels.

Full original guide (expanded)

Calculator

Results

LDL Cholesterol N/A

Data Source and Methodology

All calculations are based on the Friedewald Equation as detailed in the original publication by Friedewald et al., published in 1972.

The Formula Explained

\( \text{LDL} = \text{Total Cholesterol} - \text{HDL} - \left(\frac{\text{Triglycerides}}{5}\right) \)

Glossary of Terms

  • Total Cholesterol: The overall level of cholesterol in your blood.
  • HDL Cholesterol: High-density lipoprotein, often referred to as 'good' cholesterol.
  • Triglycerides: A type of fat found in your blood.
  • LDL Cholesterol: Low-density lipoprotein, often referred to as 'bad' cholesterol.

How It Works: A Step-by-Step Example

Suppose a patient has a Total Cholesterol of 200 mg/dL, HDL of 50 mg/dL, and Triglycerides of 150 mg/dL. Applying the formula:

LDL = 200 - 50 - (150 / 5) = 120 mg/dL

Frequently Asked Questions (FAQ)

How is LDL cholesterol calculated?

LDL cholesterol is calculated using the Friedewald Equation: LDL = Total Cholesterol - HDL - (Triglycerides/5).

What are the normal levels of LDL cholesterol?

Normal LDL levels are generally considered to be less than 100 mg/dL.

Why is LDL cholesterol called 'bad' cholesterol?

LDL cholesterol is called 'bad' because high levels can lead to plaque buildup in arteries and result in heart disease.

Can this calculator be used for everyone?

This calculator is not suitable for patients with triglycerides levels above 400 mg/dL.

How often should I check my cholesterol levels?

It's recommended to check your cholesterol levels once every 4-6 years for adults over 20.


Audit: Complete
Formula (LaTeX) + variables + units
This section shows the formulas used by the calculator engine, plus variable definitions and units.
Formula (extracted LaTeX)
\[','\]
','
Formula (extracted text)
\( \text{LDL} = \text{Total Cholesterol} - \text{HDL} - \left(\frac{\text{Triglycerides}}{5}\right) \)
Formula (extracted text)
LDL = 200 - 50 - (150 / 5) = 120 mg/dL
Variables and units
  • No variables provided in audit spec.
Sources (authoritative):
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn

Calculator

Results

LDL Cholesterol N/A

Data Source and Methodology

All calculations are based on the Friedewald Equation as detailed in the original publication by Friedewald et al., published in 1972.

The Formula Explained

\( \text{LDL} = \text{Total Cholesterol} - \text{HDL} - \left(\frac{\text{Triglycerides}}{5}\right) \)

Glossary of Terms

  • Total Cholesterol: The overall level of cholesterol in your blood.
  • HDL Cholesterol: High-density lipoprotein, often referred to as 'good' cholesterol.
  • Triglycerides: A type of fat found in your blood.
  • LDL Cholesterol: Low-density lipoprotein, often referred to as 'bad' cholesterol.

How It Works: A Step-by-Step Example

Suppose a patient has a Total Cholesterol of 200 mg/dL, HDL of 50 mg/dL, and Triglycerides of 150 mg/dL. Applying the formula:

LDL = 200 - 50 - (150 / 5) = 120 mg/dL

Frequently Asked Questions (FAQ)

How is LDL cholesterol calculated?

LDL cholesterol is calculated using the Friedewald Equation: LDL = Total Cholesterol - HDL - (Triglycerides/5).

What are the normal levels of LDL cholesterol?

Normal LDL levels are generally considered to be less than 100 mg/dL.

Why is LDL cholesterol called 'bad' cholesterol?

LDL cholesterol is called 'bad' because high levels can lead to plaque buildup in arteries and result in heart disease.

Can this calculator be used for everyone?

This calculator is not suitable for patients with triglycerides levels above 400 mg/dL.

How often should I check my cholesterol levels?

It's recommended to check your cholesterol levels once every 4-6 years for adults over 20.


Audit: Complete
Formula (LaTeX) + variables + units
This section shows the formulas used by the calculator engine, plus variable definitions and units.
Formula (extracted LaTeX)
\[','\]
','
Formula (extracted text)
\( \text{LDL} = \text{Total Cholesterol} - \text{HDL} - \left(\frac{\text{Triglycerides}}{5}\right) \)
Formula (extracted text)
LDL = 200 - 50 - (150 / 5) = 120 mg/dL
Variables and units
  • No variables provided in audit spec.
Sources (authoritative):
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn

Calculator

Results

LDL Cholesterol N/A

Data Source and Methodology

All calculations are based on the Friedewald Equation as detailed in the original publication by Friedewald et al., published in 1972.

The Formula Explained

\( \text{LDL} = \text{Total Cholesterol} - \text{HDL} - \left(\frac{\text{Triglycerides}}{5}\right) \)

Glossary of Terms

  • Total Cholesterol: The overall level of cholesterol in your blood.
  • HDL Cholesterol: High-density lipoprotein, often referred to as 'good' cholesterol.
  • Triglycerides: A type of fat found in your blood.
  • LDL Cholesterol: Low-density lipoprotein, often referred to as 'bad' cholesterol.

How It Works: A Step-by-Step Example

Suppose a patient has a Total Cholesterol of 200 mg/dL, HDL of 50 mg/dL, and Triglycerides of 150 mg/dL. Applying the formula:

LDL = 200 - 50 - (150 / 5) = 120 mg/dL

Frequently Asked Questions (FAQ)

How is LDL cholesterol calculated?

LDL cholesterol is calculated using the Friedewald Equation: LDL = Total Cholesterol - HDL - (Triglycerides/5).

What are the normal levels of LDL cholesterol?

Normal LDL levels are generally considered to be less than 100 mg/dL.

Why is LDL cholesterol called 'bad' cholesterol?

LDL cholesterol is called 'bad' because high levels can lead to plaque buildup in arteries and result in heart disease.

Can this calculator be used for everyone?

This calculator is not suitable for patients with triglycerides levels above 400 mg/dL.

How often should I check my cholesterol levels?

It's recommended to check your cholesterol levels once every 4-6 years for adults over 20.


Audit: Complete
Formula (LaTeX) + variables + units
This section shows the formulas used by the calculator engine, plus variable definitions and units.
Formula (extracted LaTeX)
\[','\]
','
Formula (extracted text)
\( \text{LDL} = \text{Total Cholesterol} - \text{HDL} - \left(\frac{\text{Triglycerides}}{5}\right) \)
Formula (extracted text)
LDL = 200 - 50 - (150 / 5) = 120 mg/dL
Variables and units
  • No variables provided in audit spec.
Sources (authoritative):
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido on 2026-01-19
Profile · LinkedIn
Formulas

(Formulas preserved from original page content, if present.)

Version 0.1.0-draft
Citations

Add authoritative sources relevant to this calculator (standards bodies, manuals, official docs).

Changelog
  • 0.1.0-draft — 2026-01-19: Initial draft (review required).