LDL Calculator (mmol/L)

Enter values

Total Cholesterol (TC)

HDL

Triglycerides (TG)

Units

Optional: Non-HDL (if known)

Calculation method

Fasting sample

LDL goal (optional)

Or select risk profile

Formula used

Friedewald (mmol/L): LDL = TC − HDL − TG/2.2.

If Non‑HDL is provided: LDL ≈ Non‑HDL − TG/2.2 (VLDL estimate).

Unit conversions: cholesterol mg/dL ↔ mmol/L uses 38.67. Triglycerides mg/dL ↔ mmol/L uses 88.57.

Accuracy declines when triglycerides exceed about 4.5 mmol/L (≈ 400 mg/dL) or in dyslipidemias.

How to use

Choose units (mmol/L or mg/dL).
Enter TC, HDL, and TG; optionally enter Non‑HDL.
Select method. Friedewald is standard for routine fasting samples.
Optionally set an LDL goal or choose a risk profile.
Press Calculate to view LDL, ratios, and estimates.
Export results (CSV/JSON/PDF) or append to the table.

Example data table

TC	HDL	TG	Units	LDL (mmol/L)
5.2	1.3	1.6	mmol/L	3.173
200	50	150	mg/dL	3.103
4.8	1.1	1.2	mmol/L	3.155

Download CSV

Quick unit converter

Chol mmol/L

Chol mg/dL

Uses factor 38.67 for cholesterol conversion.

Notes and references

Use clinical judgment. Laboratory direct LDL assays may be preferred in hypertriglyceridemia.
Non-HDL cholesterol equals Total Cholesterol minus HDL.
Result categories depend on guidelines; thresholds vary by risk profile.

Conversion factors and constants

Quantity	mmol/L → mg/dL	mg/dL → mmol/L
Cholesterol (TC/HDL/LDL)	× 38.67	÷ 38.67
Triglycerides (TG)	× 88.57	÷ 88.57
VLDL estimate	VLDL ≈ TG/2.2 (when TG in mmol/L)

LDL interpretation bands (mmol/L)

Band	LDL (mmol/L)	Notes
Optimal (general)	< 2.6	Many guidelines prefer lower in high risk
Near optimal	2.6 – 3.3	Consider overall risk profile
Borderline high	3.4 – 4.0	Lifestyle plus clinician advice
High	4.1 – 4.9	Clinical management often indicated
Very high	≥ 5.0	Urgent clinical review typically needed

When to avoid the Friedewald estimate

Triglycerides above ~4.5 mmol/L (≈ 400 mg/dL).
Non-fasting samples with markedly elevated triglycerides.
Known dyslipidemias (e.g., type III, severe hypertriglyceridemia).
Post-acute illness or during pregnancy without clinician guidance.

Inputs and units cheatsheet

Input	Typical range (mmol/L)	Entry tips
Total Cholesterol (TC)	3.0 – 7.0	From lab report; select correct units
HDL	0.8 – 2.5	High HDL improves ratios
Triglycerides (TG)	0.5 – 4.5	Prefer fasting for estimate accuracy
Non‑HDL (optional)	2.0 – 5.5	Auto-computed if TC and HDL provided

Frequently Asked Questions

1) What formula does this calculator use?

It uses Friedewald LDL = TC − HDL − TG/2.2 in mmol/L, with mg/dL conversions using 38.67 for cholesterol and 88.57 for triglycerides. Accuracy declines when triglycerides exceed about 4.5 mmol/L or in dyslipidemias.

2) Can I enter mg/dL values?

Yes; select mg/dL in Units. The calculator converts internally to mmol/L, applies the formula, then shows LDL and non‑HDL in both units. The quick converter box helps convert single values fast.

3) When should I avoid this estimate?

Avoid with triglycerides above ~4.5 mmol/L, non‑fasting very high triglycerides, type III dyslipidemia, severe hypertriglyceridemia, pregnancy, or acute illness. Consider direct LDL measurement per your laboratory or clinician.

4) What is non‑HDL cholesterol?

Non‑HDL equals Total Cholesterol minus HDL. It captures atherogenic lipoproteins, including LDL, VLDL, and remnants. It stays informative when triglycerides are high and is often a secondary treatment target.

5) How are VLDL and remnant estimated?

VLDL cholesterol is approximated as TG/2.2 when triglycerides are in mmol/L. Remnant cholesterol equals Non‑HDL minus LDL. These are estimates and may differ from direct laboratory measurements.

6) What are typical LDL goals?

Common targets include ≤3.0 mmol/L (low risk), ≤2.6 mmol/L (moderate), ≤1.8 mmol/L (high), and ≤1.4 mmol/L (very high). Follow local guidelines and personalized advice from your clinician.

7) How do I export or save results?

Use Download CSV for examples, Export table for dynamic entries, Export results for JSON, and Download PDF to open a print view. Then use your browser’s Save as PDF.