LDL Cholesterol Calculator
Estimate LDL cholesterol with the Friedewald equation.
Results update as you type.
This calculator provides estimates based on population research. Results are not medical advice. Consult a qualified healthcare provider before making health or nutrition decisions.
How it works
LDL cholesterol, the 'bad' cholesterol most associated with heart disease, is usually estimated rather than measured directly, and this calculator uses the standard Friedewald equation to do so. You enter your total cholesterol, HDL, and triglycerides, all in mg/dL, and it returns your LDL, your VLDL, and your non-HDL cholesterol. The Friedewald formula computes LDL as total cholesterol minus HDL minus VLDL, with VLDL estimated as triglycerides divided by five. This is the method most labs have historically used, which is why a standard lipid panel measures total, HDL, and triglycerides and reports LDL as a calculation. The equation is accurate only when triglycerides are below 400 mg/dL; above that, the VLDL approximation fails and a direct LDL measurement is needed, so this calculator returns no value for very high triglycerides. LDL matters because it carries cholesterol into artery walls, where it can form plaque and raise the risk of heart attack and stroke, so lower LDL is generally better. The calculator also gives non-HDL cholesterol, total minus HDL, which many guidelines now emphasize. Use these estimates to understand your lipid panel, but always interpret them with your doctor, who can set targets based on your overall risk. Enter your total cholesterol, HDL, and triglycerides to estimate your LDL.
LDL = total − HDL − (triglycerides / 5) (valid for TG < 400 mg/dL)
The Friedewald equation estimates LDL cholesterol as total cholesterol minus HDL minus VLDL, where VLDL is approximated as triglycerides divided by 5 in mg/dL. It is valid only when triglycerides are below 400 mg/dL, because the VLDL estimate breaks down at higher levels, so the calculator returns no value above that threshold.
Source:Friedewald equation (NIH / NHLBI)
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter total cholesterol, hdl cholesterol and triglycerides.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
LDL cholesterol updates instantly as you type — no button to press.
Frequently asked questions
What is the Friedewald equation?
The Friedewald equation estimates LDL cholesterol as total cholesterol minus HDL minus VLDL, where VLDL is taken as triglycerides divided by five in mg/dL. It has long been the standard way labs calculate LDL from a lipid panel, avoiding the cost of measuring LDL directly. The calculator applies this formula to your values.
Why does the calculator need triglycerides below 400?
The Friedewald equation estimates VLDL as triglycerides divided by five, an approximation that holds only when triglycerides are below 400 mg/dL. Above that level, the estimate becomes unreliable and can misstate LDL, so a direct LDL measurement is required instead. The calculator returns no value when triglycerides are 400 or higher to avoid giving an inaccurate result.
Why is LDL cholesterol important?
LDL, low-density lipoprotein, carries cholesterol into the walls of arteries, where excess can build up as plaque, narrowing vessels and raising the risk of heart attack and stroke. Because of this, LDL is often called the 'bad' cholesterol, and lowering it is a central goal of heart-disease prevention through diet, exercise, and sometimes medication.
What is VLDL cholesterol?
VLDL, very-low-density lipoprotein, is a type of cholesterol-carrying particle rich in triglycerides. It is not usually measured directly, so the Friedewald equation estimates it as triglycerides divided by five. Like LDL, VLDL contributes to plaque formation, which is why non-HDL cholesterol, which includes VLDL, is considered a useful risk marker.
Should I rely on this instead of a lab test?
No. This calculator reproduces the standard formula labs use, but you still need an actual lipid panel to obtain your total, HDL, and triglyceride values, and your doctor should interpret the results. It is helpful for understanding how LDL is derived and checking your reported number, not for replacing professional testing and medical advice.