LDL Cholesterol, Calculated, Serum/Plasma
A blood test that estimates LDL (“bad”) cholesterol using the results of a lipid panel to help assess cardiovascular risk.
["This test estimates the amount of LDL cholesterol in your blood and helps guide heart-risk and treatment decisions."]
Key facts at a glance
- LOINC
- 47213-4
- Short code
- LDLc real size Pat SerPl
- Synonyms
- LDLc real size Pat SerPl
- Category
- lipid
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0
- Ref high
- 100
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83721
- SNOMED
- 113079007
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What is this test?
LDL cholesterol is a type of cholesterol that can build up in artery walls and contribute to heart disease. This test usually calculates an LDL cholesterol estimate from your total cholesterol, HDL cholesterol, and triglyceride results.
Why might I need this test?
Calculated LDL cholesterol is commonly used to evaluate cardiovascular risk, diagnose or monitor lipid disorders, and guide cholesterol-lowering treatment. Your clinician will interpret it along with your other cholesterol results and health history.
How is the test performed?
A blood sample is drawn from a vein, usually from the inside of your elbow. The laboratory measures the components of a lipid panel and uses a formula to calculate the LDL cholesterol estimate. In some situations, LDL cholesterol may also be measured directly.
How do I prepare for the test?
Follow your clinician’s or laboratory’s fasting instructions. Some lipid tests require fasting, commonly for 8 to 12 hours, while others do not. Water is generally allowed, and you should not stop prescribed medicines unless your clinician tells you to do so.
Reference range
Optimal: <100 mg/dLN/A
Fasting for 12-14 hours preferred. Water is permitted. Avoid alcohol for 24 hours before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A high calculated LDL cholesterol result may indicate increased risk of plaque buildup in the arteries, also called atherosclerosis. Very low LDL cholesterol can occur with low-fat diets, malabsorption, certain medicines, or uncommon genetic conditions. The calculation can be less reliable when triglycerides are very high or the lipid-panel values are unusual, so a direct LDL measurement may sometimes be needed.
Short name
Calculated LDL cholesterol
Frequently asked questions
Is calculated LDL cholesterol the same as a direct LDL test?
Do I need to fast for this test?
What causes LDL cholesterol to be high?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy