MELD Calculator

Calculate a MELD score to estimate the severity of end-stage liver disease using standard lab values.

What Is the MELD Score?

The Model for End-Stage Liver Disease (MELD) score is a validated numerical scale used to estimate the severity of chronic liver disease. It predicts short-term mortality risk in patients awaiting liver transplantation. The score is calculated from three routine laboratory values: serum bilirubin, serum creatinine, and the international normalized ratio (INR) for prothrombin time.

Originally developed to assess prognosis in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) procedures, the MELD score is now the standard tool used by transplant centers to prioritize organ allocation. A higher score indicates more severe liver dysfunction and a greater urgency for transplantation.

How the MELD Score Is Calculated

The MELD score uses a logarithmic formula that accounts for the nonlinear relationship between lab values and mortality risk. The standard formula is:

MELD = 3.78 × ln(serum bilirubin [mg/dL]) + 11.2 × ln(INR) + 9.57 × ln(serum creatinine [mg/dL]) + 6.43

Key calculation rules:

All lab values are capped at a minimum of 1.0 to prevent negative logarithms.
Serum creatinine is capped at 4.0 mg/dL.
Patients who have received dialysis twice within the prior week automatically have their creatinine set to 4.0 mg/dL.
The final score is rounded to the nearest integer.
Scores are capped at a maximum of 40.

An exception exists for patients with certain etiologies: the MELD-Na score incorporates serum sodium for additional prognostic accuracy, though the standard MELD remains the primary allocation tool in most regions.

How to Use This Calculator

Enter the three required lab values as they appear on the patient's most recent laboratory report. Ensure units are correct — bilirubin and creatinine must be in mg/dL. If your lab reports in µmol/L, convert before entering. The calculator applies the standard formula and rounding rules automatically.

No additional clinical information is needed. The result is a single integer between 6 and 40 that corresponds to a predicted three-month mortality risk.

Understanding Your MELD Score Result

The MELD score directly correlates with mortality risk. General interpretation guidelines:

MELD < 10: Low short-term mortality risk. Transplantation is rarely urgent.
MELD 10–19: Moderate risk. May qualify for listing depending on other clinical factors.
MELD 20–29: High risk. Significant mortality within three months without transplant.
MELD 30–39: Very high risk. Urgent transplant evaluation warranted.
MELD 40: Critical risk. Highest priority for organ allocation.

The score is a statistical estimate, not a precise prediction for an individual patient. Clinical judgment, including complications like ascites, encephalopathy, and variceal bleeding, remains essential for comprehensive assessment.

Common Mistakes When Calculating MELD

Using incorrect units: Bilirubin and creatinine must be in mg/dL. Using µmol/L without conversion produces a falsely low score.
Ignoring the 1.0 minimum: Values below 1.0 are set to 1.0 before calculation. Entering the actual low value without adjustment yields an incorrect result.
Not accounting for dialysis: Patients on chronic hemodialysis should have creatinine entered as 4.0 mg/dL, not their measured value.
Confusing MELD with MELD-Na: This calculator uses the standard MELD formula. MELD-Na includes sodium and produces a different score.

Limitations of the MELD Score

The MELD score has several important limitations:

It does not account for complications of portal hypertension such as ascites, hepatic encephalopathy, or variceal bleeding.
It may underestimate severity in patients with hepatocellular carcinoma (HCC) who receive exception points.
It is less accurate in acute liver failure compared to chronic disease.
Creatinine-based scoring can be affected by muscle mass, making it less reliable in malnourished or sarcopenic patients.
The score does not reflect quality of life or functional status.

Despite these limitations, the MELD score remains the most widely accepted objective tool for liver transplant prioritization due to its reproducibility and strong correlation with mortality.

Practical Use Cases

Transplant listing decisions: Hepatologists use MELD to determine when a patient should be listed for transplant.
Organ allocation: UNOS and other transplant networks use MELD to prioritize candidates on the waiting list.
Prognostic counseling: Clinicians use the score to discuss expected disease trajectory with patients and families.
Research and registry data: MELD is used as a standardized severity measure in clinical studies and quality reporting.

Frequently Asked Questions

What is a normal MELD score?

A MELD score of 6 or 7 is considered normal in a healthy individual. Scores below 10 generally indicate low short-term mortality risk. Scores above 15 are typically required for transplant listing in most centers.

Can the MELD score change over time?

Yes. The MELD score is dynamic and can improve or worsen as liver function changes. Patients are re-scored periodically while on the waiting list. A rising score indicates disease progression and may increase transplant priority.

What is the difference between MELD and MELD-Na?

MELD-Na incorporates serum sodium into the calculation because hyponatremia is independently associated with mortality in liver disease. MELD-Na may provide better prognostic accuracy in patients with low sodium levels, but the standard MELD remains the primary allocation tool in most regions.

Why is creatinine capped at 4.0 mg/dL?

Creatinine levels above 4.0 mg/dL do not add additional discriminatory power for mortality prediction. The cap prevents extreme values from disproportionately influencing the score and reflects the fact that renal function beyond this threshold does not further differentiate risk.

Is the MELD score used for children?

No. The Pediatric End-Stage Liver Disease (PELD) score is used for children under 12 years of age. PELD incorporates additional factors such as growth failure and albumin levels.