MELD Score

Q: What happens to bilirubin, INR, and creatinine values below 1.0?

In the standard MELD calculation, bilirubin, INR, and creatinine are floored at 1.0 before the logarithms are taken, so a very low creatinine cannot lower the score below what a value of 1.0 would produce. Creatinine is also capped at 4.0, and is set to 4.0 when dialysis was required at least twice in the last week.

Q: How does MELD differ from the current U.S. allocation score?

The classic MELD formula uses bilirubin, INR, and creatinine with fixed coefficients. Current U.S. liver allocation uses the MELD 3.0 model, adopted in July 2023, which incorporates albumin, sex, and updated coefficients. The classic score remains a valid prognostic estimate of 3-month mortality in chronic liver disease, but it is no longer the allocation score.

Q: Why can MELD underestimate risk in some patients?

Creatinine depends on muscle mass, so patients with low muscle mass can have a deceptively low creatinine and therefore a lower MELD than their true severity warrants. The score also omits ascites and hepatic encephalopathy, which carry independent prognostic information, and INR assays vary between laboratories, which affects reproducibility of the score over time.

Model for End-stage Liver Disease (MELD) score for predicting 3-month mortality in patients with advanced liver disease.

Gastroenterology GastroenterologyEvidence-BasedUpdated 2026-07

Clinical decision-support tool for qualified healthcare professionals. Results are not a diagnosis and should not replace professional clinical judgment.

Clinical Notes

The MELD score estimates 3-month mortality in patients with chronic, noncholestatic liver disease and is used for transplant waitlist prioritization. It is derived from a single set of laboratory values and does not capture all factors relevant to transplant candidacy (e.g., sodium, encephalopathy, ascites, functional status). The dialysis rule and creatinine capping reflect UNOS allocation practice; results should be interpreted by clinicians experienced in hepatology.

Calculator Information

Specialty

Gastroenterology

📋 Reference Ranges

Reference ranges for this calculator
Classification	Range
Low Risk	<10
Moderate Risk	10–19
High Risk	20–29
Very High Risk	30–39
Extremely High Risk	≥40

What This Calculator Measures

Calculates the Model for End-stage Liver Disease (MELD) score to estimate 3-month mortality in adults with chronic liver disease and to guide liver transplant prioritization.

How to Use

Use the most recent serum bilirubin, creatinine, and INR from the same clinical assessment.
Indicate whether the patient has been on dialysis at least twice in the past week — the calculator sets creatinine to 4 mg/dL in that case, per UNOS convention.
Note that bilirubin and INR are floored at 1 and non-dialysis creatinine is capped at 4 mg/dL before scoring.
Review the score against the mortality-risk bands and the patient's clinical trajectory.

How the Calculation Works

MELD = 3.78 x ln(bilirubin) + 11.2 x ln(INR) + 9.57 x ln(creatinine) + 6.43, with bilirubin and creatinine in mg/dL. Bilirubin, INR, and creatinine are floored at 1.0, creatinine is capped at 4.0 (and set to 4.0 when dialysis was required), and the result is rounded to the nearest integer.

Variables Explained

Serum Bilirubin

Serum bilirubin in mg/dL, entered into a natural logarithm and floored at 1.0.

Common error: Values below 1.0 are raised to 1.0, so very low bilirubin does not further lower the score.

Serum Creatinine

Serum creatinine in mg/dL; floored at 1.0 and capped at 4.0, or set to 4.0 when on dialysis.

INR

International normalized ratio, entered into a natural logarithm and floored at 1.0.

Dialysis at least twice in the last week?

Yes forces the creatinine term to 4.0, reflecting transplant allocation practice.

Interpretation Guide

MELD <10 indicates low 3-month mortality risk; 10–19 moderate; 20–29 high; 30–39 very high; ≥40 extremely high risk. Higher scores warrant expedited transplant evaluation.

Clinical Significance

MELD is a well-validated mortality-risk score that estimates 3-month survival in chronic liver disease and historically underpinned liver transplant prioritization in the United States. Current U.S. liver allocation uses the MELD 3.0 model (adopted July 2023), which incorporates albumin, sex, and updated coefficients rather than the classic MELD formula.

When It Is Useful

Liver transplant listing and risk stratification
Prognosis in decompensated cirrhosis
Serial monitoring of disease severity over time
Risk stratification before major interventions in cirrhotic patients

When It Is Not Useful

Acute liver failure, which uses dedicated criteria rather than MELD
Pediatric patients, where PELD-based scores apply
As a substitute for a full clinical assessment, including ascites and encephalopathy
Solely to predict outcomes in non-liver surgical procedures

Common Mistakes

Entering serum creatinine in micromoles per liter rather than mg/dL, which inflates the creatinine term and yields a score that cannot be compared with the risk bands.
Answering 'No' to dialysis for a patient dialyzed at least twice in the last week, because the rules set creatinine to 4.0 in that situation and missing this underestimates risk.
Using MELD to grade acute liver failure, which has dedicated criteria, or expecting it to capture ascites, encephalopathy, or other factors it does not include.

Limitations

Does not include ascites or hepatic encephalopathy, which carry independent prognostic information.
Creatinine depends on muscle mass, so MELD may under-estimate risk in low-muscle-mass patients.
INR assays vary between laboratories, affecting reproducibility.
The score is validated for chronic liver disease, not acute liver failure.

Worked Example

A 55-year-old man with decompensated alcoholic cirrhosis is being evaluated for transplant listing. Bilirubin is 2.5 mg/dL, creatinine 1.2 mg/dL, INR 1.5, and he is not on dialysis.

Inputs:

bilirubin: 2.5

creatinine: 1.2

inr: 1.5

dialysis: no

Expected Result: MELD = 3.78×ln(2.5) + 11.2×ln(1.5) + 9.57×ln(1.2) + 6.43 ≈ 16 — moderate 3-month mortality risk (band 10–19).

Evidence & References

Source:: Original MELD Description / UNOS
Content updated:: 2026-08

Kamath PS, et al. Hepatology. 2001.

References

Kamath PS, et al. A model to predict survival in patients with end-stage liver disease. Hepatology. 2001. (Original model)

Frequently Asked Questions

What happens to bilirubin, INR, and creatinine values below 1.0?

In the standard MELD calculation, bilirubin, INR, and creatinine are floored at 1.0 before the logarithms are taken, so a very low creatinine cannot lower the score below what a value of 1.0 would produce. Creatinine is also capped at 4.0, and is set to 4.0 when dialysis was required at least twice in the last week.

How does MELD differ from the current U.S. allocation score?

The classic MELD formula uses bilirubin, INR, and creatinine with fixed coefficients. Current U.S. liver allocation uses the MELD 3.0 model, adopted in July 2023, which incorporates albumin, sex, and updated coefficients. The classic score remains a valid prognostic estimate of 3-month mortality in chronic liver disease, but it is no longer the allocation score.

Why can MELD underestimate risk in some patients?

Creatinine depends on muscle mass, so patients with low muscle mass can have a deceptively low creatinine and therefore a lower MELD than their true severity warrants. The score also omits ascites and hepatic encephalopathy, which carry independent prognostic information, and INR assays vary between laboratories, which affects reproducibility of the score over time.

Disclaimer: This calculator is intended for educational and clinical decision support purposes only. Classic MELD is a prognostic mortality-risk score; current U.S. liver allocation uses the MELD 3.0 model. Transplant decisions must incorporate the full clinical picture and institutional policies.