MELD Score Calculator — Liver Disease Severity
Compute the MELD (Model for End-Stage Liver Disease) score and MELD-Na from serum bilirubin, INR, creatinine and sodium — the standard used by UNOS to prioritise liver transplant waiting lists.
mg/dL
mg/dL
mEq/L
On dialysis ≥2× in past 7 days?
Model for End-Stage Liver Disease — range 6–40; higher = more severe
- 1
Bilirubin term
3.78 × ln(1) = 0 - 2
INR term
11.2 × ln(1.1) = 1.0675 - 3
Creatinine term
9.57 × ln(1) = 0 - 4
Raw MELD sum
0 + 1.0675 + 0 + 6.43 = 7.5Lab values floored at 1.0; creatinine capped at 4.0 per UNOS rules. - 5
MELD Score (rounded, clamped 6–40)
round(7.5) = 7
How does this calculator work?
MELD = 3.78 × ln(bilirubin) + 11.2 × ln(INR) + 9.57 × ln(creatinine) + 6.43, rounded to an integer in the range 6–40. Higher scores mean more severe liver disease and greater urgency for transplantation. MELD-Na adds a serum-sodium term. Lab values below 1.0 are floored to 1.0; creatinine above 4.0 or on dialysis is capped at 4.0.
Formula
How this is calculated
The MELD score was developed at the Mayo Clinic and adopted by UNOS in 2002 to allocate deceased-donor livers by medical urgency. It uses three objective laboratory values — serum bilirubin (liver excretory function), INR (hepatic synthetic function measured via coagulation) and serum creatinine (kidney function, which often fails in advanced cirrhosis via hepatorenal syndrome) — combined with a disease-aetiology constant of 6.43. Per UNOS rules, any lab value below 1.0 is raised to 1.0 before taking the logarithm, and creatinine is capped at 4.0 mg/dL (or set to 4.0 for patients receiving dialysis at least twice in the preceding seven days). The result is rounded to the nearest integer and clamped within 6–40.
MELD-Na extends the score by incorporating serum sodium, which independently predicts waitlist mortality through a mechanism related to dilutional hyponatraemia. The formula adds a term proportional to the gap between 137 mEq/L and the patient's sodium; values outside the 125–137 range are clamped before the calculation to avoid extreme adjustments.
Published UNOS data associate MELD score ranges with 90-day waitlist mortality: below 10 roughly 1.9%, 10–19 about 6%, 20–29 around 19.6%, 30–39 approximately 52.6%, and 40 around 71.3%. These figures reflect population averages; individual prognosis depends on many additional factors including aetiology, complications and listing centre practices. This tool is for educational reference only.
Frequently asked questions
MELD requires three values drawn at the same time: serum bilirubin (mg/dL), INR (international normalised ratio) and serum creatinine (mg/dL). MELD-Na additionally uses serum sodium (mEq/L). The patient's dialysis status is also required, as it caps creatinine at 4.0.
UNOS policy caps creatinine at 4.0 mg/dL and automatically applies this value for patients receiving dialysis at least twice per week. This prevents extreme renal failure from dominating the score beyond what the formula was calibrated to predict.
MELD uses only bilirubin, INR and creatinine. MELD-Na adds serum sodium, which was shown to independently predict waitlist mortality. Since 2016 UNOS uses MELD-Na for organ allocation; a low sodium can raise the score by up to 6 points.
TG we-Calculate Editorial Team. (2026). MELD Score Calculator — Liver Disease Severity [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/meld-calculator
TG we-Calculate Editorial Team. "MELD Score Calculator — Liver Disease Severity." TG we-Calculate. 2026. https://we-calculate.com/calculator/meld-calculator.
TG we-Calculate Editorial Team, "MELD Score Calculator — Liver Disease Severity," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/meld-calculator
@misc{wecalculate_meld_calculator, title = {MELD Score Calculator — Liver Disease Severity}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/meld-calculator}}, year = {2026}, note = {TG we-Calculate} }
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