# MELD Score Calculator

Calculate the MELD and MELD-Na score for end-stage liver disease. Used by UNOS for liver transplant organ allocation. Enter bilirubin, INR, creatinine, and sodium.

## What this calculates

Calculate the Model for End-Stage Liver Disease (MELD) score, the standard tool used by UNOS to prioritize patients on the liver transplant waiting list. Enter bilirubin, INR, creatinine, and optionally sodium for the updated MELD-Na score used since 2016.

## Inputs

- **Total Bilirubin** (mg/dL) — min 0.1, max 50 — Normal range: 0.1-1.2 mg/dL. Values below 1.0 are set to 1.0 per MELD protocol.
- **INR (International Normalized Ratio)** — min 0.5, max 20 — Normal range: 0.8-1.1. Values below 1.0 are set to 1.0 per MELD protocol.
- **Serum Creatinine** (mg/dL) — min 0.1, max 20 — Normal range: 0.7-1.3 mg/dL. Values below 1.0 are set to 1.0, capped at 4.0 per MELD protocol.
- **Dialysis (at least 2x in past week)** — If yes, creatinine is automatically set to 4.0 per UNOS policy
- **Serum Sodium (for MELD-Na)** (mEq/L) — min 100, max 160 — Normal: 135-145 mEq/L. Enter for MELD-Na calculation (used since 2016). Bounded 125-137.

## Outputs

- **MELD Score** — Original MELD score (6-40 scale)
- **MELD-Na Score** — MELD with sodium correction (used by UNOS since January 2016)
- **Estimated 3-Month Mortality** — formatted as text — Approximate 3-month mortality risk without transplant
- **Transplant Priority** — formatted as text — General priority level for organ allocation

## Details

The MELD score was originally developed at the Mayo Clinic in 2001 to predict survival in patients with cirrhosis who were undergoing TIPS procedures. In 2002, UNOS (United Network for Organ Sharing) adopted it to replace the older Child-Pugh classification for liver transplant allocation in the United States.

**The MELD formula:**
MELD = 3.78 x ln(bilirubin) + 11.2 x ln(INR) + 9.57 x ln(creatinine) + 6.43

All lab values have a minimum floor of 1.0 (values below 1.0 are set to 1.0). Creatinine is capped at 4.0 mg/dL, and patients on dialysis have creatinine automatically set to 4.0. The final score is bounded between 6 and 40.

**MELD-Na:** In January 2016, UNOS updated the allocation system to include serum sodium, creating the MELD-Na score. Low sodium (hyponatremia) is common in advanced liver disease and independently predicts mortality. The sodium value is bounded between 125 and 137 mEq/L.

**What the scores mean:**
- MELD 6-9: About 1.9% chance of dying within 3 months
- MELD 10-19: About 6% three-month mortality
- MELD 20-29: About 19.6% three-month mortality
- MELD 30-39: About 52.6% three-month mortality
- MELD 40: About 71.3% three-month mortality

Higher MELD scores receive priority for available donor livers. Most transplant centers consider listing patients when their MELD score reaches 15 or higher.

This tool is for educational purposes only and should not replace professional medical advice.

## Frequently Asked Questions

**Q: What MELD score do you need for a liver transplant?**

A: There is no fixed cutoff, but most transplant centers begin evaluating patients for listing when their MELD score reaches 15. Organ allocation is based on blood type, body size, geographic distance, and MELD score. In practice, patients with MELD scores above 20-25 are more likely to receive an offer, though this varies greatly by region and blood type. In some regions, patients with scores in the high 30s may still wait months.

**Q: What is the difference between MELD and MELD-Na?**

A: The original MELD uses only bilirubin, INR, and creatinine. MELD-Na adds serum sodium to the calculation. Low sodium (hyponatremia) is a strong independent predictor of mortality in liver disease patients and was not captured by the original formula. Since January 2016, UNOS uses MELD-Na for all liver allocation decisions in the US. The sodium correction can add several points to the score for patients with sodium below 137.

**Q: Why are lab values floored at 1.0?**

A: The MELD formula uses natural logarithms, and ln(1.0) = 0. Setting all lab values to a minimum of 1.0 prevents negative logarithm values that would artificially lower the score. A bilirubin of 0.5 mg/dL (which is normal) would produce a negative logarithm and paradoxically suggest better-than-baseline liver function if allowed. The floor of 1.0 ensures the score reflects actual disease severity.

**Q: How often is the MELD score recalculated?**

A: UNOS requires MELD score updates at regular intervals based on the current score: every 7 days for scores 25+, every 30 days for scores 19-24, every 90 days for scores 11-18, and every year for scores 10 and below. Labs used for the MELD calculation must be drawn within the recertification period. Using outdated labs can result in a patient being temporarily delisted.

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Source: https://vastcalc.com/calculators/health/meld-score
Category: Health & Fitness
Last updated: 2026-04-08