MELD-Na Calculator

MELD-Na	Severity	Approx. 90-day mortality
≤ 9	Low severity	≈ 1.9%
10 – 19	Moderate severity	≈ 6.0%
20 – 29	High severity	≈ 19.6%
30 – 39	Very high severity	≈ 52.6%
40 (max)	Very high severity	≈ 71.3%

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Walk-through

How to Use This Calculator

3 steps

1

Enter the four laboratory values

Type the patient's total bilirubin (mg/dL), INR, creatinine (mg/dL), and serum sodium (mEq/L) from a recent lab panel. Bilirubin, INR, and creatinine are automatically floored at 1.0, and creatinine is capped at 4.0 — you can enter the raw lab value and the calculator applies the policy bounds.

2

Check the dialysis box if it applies

Tick the dialysis toggle when the patient received two or more dialysis sessions in the prior week, or 24 hours of continuous venovenous hemodialysis (CVVHD). This overrides the entered creatinine and sets it to 4.0 mg/dL, matching UNOS/OPTN convention for renal replacement therapy.

3

Read the MELD-Na score, severity, and breakdown

The result card shows the MELD-Na score (6–40), the severity band, the underlying base MELD, and the approximate 90-day mortality. Open the Raw MELD tab to see which floors and caps were applied and whether the sodium adjustment fired, and the Score Components tab for the per-term contribution table.

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Reference

Formula & Methodology

3 formulas

Base MELD score

MELD = round[ (0.957 × ln(Cr) + 0.378 × ln(bilirubin) + 1.120 × ln(INR) + 0.643) × 10 ]

The base MELD combines creatinine, bilirubin, and INR on a natural-log scale. Each lab is floored at 1.0 before the log is taken, creatinine is capped at 4.0 mg/dL (or set to 4.0 on dialysis), and the rounded result is bounded to 6–40. The equivalent published coefficient form is 9.57·ln(Cr) + 3.78·ln(bili) + 11.2·ln(INR) + 6.43.

Sodium adjustment (MELD-Na)

MELD-Na = MELD + 1.32 × (137 − Na) − [ 0.033 × MELD × (137 − Na) ]

When the base MELD is greater than 11, hyponatremia raises the score through this adjustment. Serum sodium is bounded to the 125–137 mEq/L range first, so values outside that window are clamped. If the base MELD is 11 or below, the adjustment is skipped and MELD-Na equals the base MELD.

Final bounds

6 ≤ MELD-Na ≤ 40

The final MELD-Na is rounded to the nearest whole number and constrained between a minimum of 6 and a maximum of 40, the range used for waitlist allocation. A score of 40 represents the ceiling used for the highest-priority candidates.

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High YMYL

Trust, Methodology & Sources

Reviewed by Calculover Editorial Review · Updated 2026-07-22 · 3 sources

Editorial accountability

Author: Calculover Clinical Team - Clinical content team

Owner: Calculover Editorial - Editorial oversight

Reviewer: Calculover Editorial Review - Clinical-source review

Last reviewed: 2026-07-22

Last verified: 2026-07-22

Data effective: 2026-07-22

Methodology

The calculator implements the UNOS/OPTN MELD-Na score (in use since January 2016). The base MELD is 0.957·ln(Cr) + 0.378·ln(bilirubin) + 1.120·ln(INR) + 0.643, multiplied by 10 and rounded; bilirubin, INR, and creatinine are floored at 1.0; creatinine is capped at 4.0 mg/dL (or set to 4.0 for dialysis ≥ 2× in the prior week). When the base MELD exceeds 11, the sodium adjustment MELD-Na = MELD + 1.32·(137 − Na) − [0.033·MELD·(137 − Na)] is applied with sodium bounded to 125–137 mEq/L, and the final score is bounded to 6–40. Every floor, cap, threshold, and coefficient was cross-verified against the OPTN liver allocation policy and MDCalc, and the worked examples were checked digit-for-digit.

Assumption: Bilirubin, INR, and creatinine are entered in standard U.S. units (mg/dL, unitless, mg/dL) and sodium in mEq/L from a recent laboratory panel.

Assumption: The dialysis toggle represents two or more dialysis sessions in the prior week or 24 hours of CVVHD, which sets creatinine to 4.0 mg/dL per policy.

Assumption: A single MELD-Na value is treated as a prognostic and prioritization data point, not a diagnosis.

Limitations & guidance

The score does not include MELD exception points (e.g., for hepatocellular carcinoma, hepatopulmonary syndrome, or other approved conditions) that transplant centers may add on top of the laboratory MELD-Na.

MELD-Na predates and does not capture every complication of cirrhosis, such as refractory ascites or recurrent encephalopathy, and can be distorted by non-hepatic causes of an abnormal creatinine or INR (for example, anticoagulation raising the INR).

Results are for clinical decision support and education only; actual transplant listing uses lab-certified values through the official UNOS system and the judgment of a transplant team.

Professional guidance: This calculator is for education and clinical decision support only and is not medical advice, diagnosis, or treatment. MELD-Na scores support, but do not replace, the judgment of a licensed clinician and the official UNOS transplant-listing process; it must never be used to make an actual listing or allocation decision.

Primary sources

Policy 9: Allocation of Livers and Liver-Intestines (MELD/MELD-Na) - Organ Procurement and Transplantation Network (OPTN)

Hyponatremia and Mortality among Patients on the Liver-Transplant Waiting List - Kim WR, Biggins SW, Kremers WK, et al. N Engl J Med. 2008;359(10):1018-1026

MELD Na (UNOS/OPTN) Calculator - MDCalc

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Glossary

Key Terms Explained

7 terms

MELD-Na The Model for End-Stage Liver Disease with sodium — a score from 6 to 40 that estimates short-term mortality in chronic liver disease and, since 2016, drives U.S. liver-transplant waitlist priority.

End-stage liver disease (ESLD) Advanced, irreversible liver dysfunction (usually from cirrhosis) in which the liver can no longer sustain its metabolic and synthetic work; MELD-Na quantifies its severity for prognosis and transplant listing.

Transplant priority A candidate's rank on the liver-transplant waiting list. Higher MELD-Na scores signal higher short-term mortality and therefore move a candidate up the allocation order.

INR (International Normalized Ratio) A standardized measure of how long blood takes to clot. A rising INR reflects impaired hepatic synthesis of clotting factors and is one of the three base MELD variables.

UNOS The United Network for Organ Sharing — the non-profit that operates the U.S. organ transplant network under federal contract and processes the lab-certified values used for actual MELD-Na listing.

OPTN The Organ Procurement and Transplantation Network — the federally mandated system whose policies (administered by UNOS) define the MELD-Na formula, its bounds, and liver allocation rules.

Creatinine cap The policy rule that limits creatinine to a maximum of 4.0 mg/dL in the MELD formula, and sets it to 4.0 when a patient has had two or more dialysis sessions in the prior week.

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Scenarios

Real-World Examples

3 worked examples

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Moderate disease

Cirrhosis with mild hyponatremia

Bilirubin 3.0 mg/dL INR 1.5 Creatinine 2.0 mg/dL Sodium 130 mEq/L

The base MELD is 22. Because it exceeds 11, the sodium adjustment applies: with sodium 130, MELD-Na rises to 26 — the high-severity band, with an approximate 90-day mortality near 19.6%. The 4-point bump from hyponatremia meaningfully raises transplant priority.

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Severe disease

Decompensated cirrhosis, transplant-range score

Bilirubin 8.0 mg/dL INR 2.2 Creatinine 3.0 mg/dL Sodium 128 mEq/L

The base MELD is 34. The sodium adjustment for a sodium of 128 lifts MELD-Na to 36 — deep in the very-high-severity band (approximate 90-day mortality near 52.6%). Scores in this range carry high liver-transplant priority; listing decisions use lab-certified values through UNOS.

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Dialysis-adjusted

Hepatorenal syndrome on dialysis

Bilirubin 4.0 mg/dL INR 2.0 Creatinine on dialysis → 4.0 Sodium 133 mEq/L

Because the patient is on dialysis, creatinine is set to 4.0 mg/dL regardless of the measured value, giving a base MELD of 33. The sodium adjustment for a sodium of 133 raises MELD-Na to 34 — the very-high-severity band. The dialysis rule prevents renal replacement therapy from artificially lowering the score.

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Deep Dive

Understanding the MELD-Na Score

3 chapters · 4 min read

The MELD-Na score turns four routine lab values into a single number that reflects how sick a patient's liver is and how urgently they may need a transplant. Since January 2016, U.S. transplant centers have used MELD-Na — the original MELD score adjusted for serum sodium — to rank candidates on the liver-transplant waiting list, because low sodium (hyponatremia) independently predicts higher waitlist mortality that the original MELD missed.

How the MELD-Na score works

The base MELD score combines three labs on a natural-log scale: creatinine (kidney function), bilirubin (how well the liver clears waste), and INR (how well the liver makes clotting factors). Each value is floored at 1.0 before the logarithm, creatinine is capped at 4.0 mg/dL, and the rounded result is bounded between 6 and 40.

MELD-Na then layers on a sodium adjustment. When the base MELD is above 11, the formula adds points for hyponatremia using a bounded sodium of 125–137 mEq/L. A patient with a base MELD of 22 and a sodium of 130, for example, ends up with a MELD-Na of 26 — the extra points reflect the worse prognosis that low sodium signals.

Why the floors, caps, and dialysis rule exist

The bounds keep the score stable and fair. Flooring bilirubin, INR, and creatinine at 1.0 avoids negative logarithms for normal or low values. Capping creatinine at 4.0 mg/dL stops severe kidney failure from dominating a liver score, and the dialysis rule — creatinine set to 4.0 when a patient has had two or more sessions in the prior week — prevents dialysis from artificially lowering creatinine and understating illness. Bounding sodium to 125–137 mEq/L and applying the adjustment only above a base MELD of 11 limits noise at low scores.

How it is used and its limits

MELD-Na is a prioritization and prognosis tool: higher scores mean higher short-term mortality and higher position on the transplant list. It is not a diagnosis and does not capture everything — complications such as refractory ascites, hepatic encephalopathy, or hepatocellular carcinoma may justify additional "exception" points that the raw score does not include. Actual listing uses lab-certified values processed through the official UNOS system and clinical judgment from a transplant team. Treat the number here as an educational and decision-support reference, not a substitute for that process.

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Questions

Frequently Asked Questions

6 questions

What is the MELD-Na formula?+

The base MELD is 3.78 × ln(bilirubin) + 11.2 × ln(INR) + 9.57 × ln(creatinine) + 6.43, rounded to the nearest whole number. If the base MELD is greater than 11, a sodium adjustment is added: MELD-Na = MELD + 1.32 × (137 − Na) − [0.033 × MELD × (137 − Na)]. The final score is bounded to 6–40.

Are the lab values floored?+

Yes. Bilirubin, INR, and creatinine are each set to a minimum of 1.0 before the logarithm is taken, because the natural log of a value below 1 is negative and the model is not defined for it. Values at or above 1.0 are used as entered.

Is creatinine capped?+

Yes. Creatinine is capped at 4.0 mg/dL. If the patient had two or more dialysis sessions in the prior week (or 24 hours of continuous venovenous hemodialysis), creatinine is automatically set to 4.0 mg/dL regardless of the measured value.

When is the sodium adjustment applied?+

The sodium adjustment is applied only when the base MELD is greater than 11. Serum sodium is first bounded to the 125–137 mEq/L range, so values below 125 are treated as 125 and values above 137 are treated as 137. When base MELD is 11 or below, MELD-Na equals the base MELD.

What is MELD-Na used for?+

MELD-Na estimates the short-term mortality risk of end-stage liver disease and is used by UNOS/OPTN to prioritize candidates on the liver-transplant waiting list. Higher scores mean higher priority. The official allocation calculation uses lab-certified values entered through the UNOS system.

Can this replace the official MELD-Na used for listing?+

No. This calculator is for clinical decision support and education only. Actual transplant-listing decisions use certified laboratory values processed through the official UNOS system and are made by a transplant team — not by a general-purpose calculator.

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Laboratory Values

MELD-Na Score

Base MELD & Applied Policy Rules

Adjustments applied to your inputs

Score Components

MELD-Na Severity & 90-Day Mortality Reference

How to Use This Calculator

Enter the four laboratory values

Check the dialysis box if it applies

Read the MELD-Na score, severity, and breakdown

Formula & Methodology

Trust, Methodology & Sources

Key Terms Explained

Real-World Examples

Moderate disease

Severe disease

Dialysis-adjusted

Understanding the MELD-Na Score

How the MELD-Na score works

Why the floors, caps, and dialysis rule exist

How it is used and its limits

Frequently Asked Questions

Get a branded PDF of your results

MELD-Na Calculator

Laboratory Values

MELD-Na Score

Base MELD & Applied Policy Rules

Adjustments applied to your inputs

Score Components

MELD-Na Severity & 90-Day Mortality Reference

How to Use This Calculator

Enter the four laboratory values

Check the dialysis box if it applies

Read the MELD-Na score, severity, and breakdown

Formula & Methodology

Trust, Methodology & Sources

Key Terms Explained

Real-World Examples

Understanding the MELD-Na Score

How the MELD-Na score works

Why the floors, caps, and dialysis rule exist

How it is used and its limits

Frequently Asked Questions

Get a branded PDF of your results

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