MELD-Na Score Calculator
Calculate Model for End-Stage Liver Disease with Sodium correction for liver transplant prioritization.
About this calculator
The MELD-Na score is the laboratory-based severity score the US organ allocation system (OPTN/UNOS) uses to rank adults awaiting a deceased-donor liver transplant -- a higher score generally means sicker and higher priority, all else equal. Calculation happens in two stages. First, the standard MELD score is computed from three labs -- creatinine, total bilirubin, and INR -- using the published coefficients (0.957 x ln(creatinine) + 0.378 x ln(bilirubin) + 1.120 x ln(INR) + 0.643, multiplied by 10). Per UNOS policy, any lab value below 1.0 is treated as 1.0 in this formula (a patient with an excellent creatinine of 0.6 is not scored as if their kidneys were "better than normal"), and creatinine is capped at 4.0 -- including for a patient who has had two or more dialysis sessions in the prior week, whose actual creatinine is ignored entirely and replaced with the 4.0 ceiling, since dialysis clears creatinine and would otherwise mask how sick the kidneys really are. Second, a sodium correction is layered on. That correction traces to a 2008 New England Journal of Medicine study by Kim and colleagues, who analyzed OPTN waitlist data and found that low sodium (hyponatremia, itself an independent marker of poor prognosis in cirrhosis) predicted mortality even after accounting for MELD -- the finding that led OPTN to add the sodium term to the score.
It applies only when the underlying MELD score is above 11 -- at or below that threshold, MELD-Na simply equals MELD and sodium plays no role at all, no matter how low it is. Sodium is bounded to 125-137 mEq/L before it enters the formula. The final score is rounded to a whole number and bounded 6-40. This calculator also shows the classic MELD three-month waitlist mortality table (roughly 1.9% for scores 6-9 up to about 71% for scores 40) and a simplified priority tier for context -- the actual US allocation process is a distance-based acuity-circle system, not a single global waitlist ranked purely by score, so real-world position depends on more than this number alone. Use this as an educational estimate of the formula, not a substitute for the value your transplant center's laboratory and coordination team report.
Medical Disclaimer
This calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about your health. Never disregard professional medical advice or delay seeking it because of results from this tool.
Inputs
Results
MELD Score
6
MELD-Na Score
6
Figures current as of 2008. Source: Kim WR, Biggins SW, Kremers WK, Wiesner RH, Kamath PS, Benson JT, Edwards E, Therneau TM. Hyponatremia and mortality among patients on the liver-transplant waiting list. N Engl J Med. 2008;359(10):1018-1026.
How to Use This Calculator
- Enter Serum Creatinine in mg/dL, Total Bilirubin in mg/dL, and INR from current labs.
- Enter Serum Sodium in mEq/L and indicate whether the patient is on Dialysis.
- Review MELD Score and MELD-Na Score — MELD-Na is used for liver transplant allocation.
- Check Estimated 3-Month Mortality percentage and Transplant Priority Level.
- Use the score to monitor disease progression at follow-up visits and guide referral timing.
How the result changes with Serum Creatinine (mg/dL)
| Serum Creatinine (mg/dL) | MELD Score | MELD-Na Score |
|---|---|---|
| 0.5 | 6 | 6 |
| 0.75 | 6 | 6 |
| 1.5 | 10 | 10 |
| 2.5 | 15 | 15 |
What each input means
- Serum Creatinine (mg/dL)
- Serum creatinine in mg/dL. Values are clamped to 1.0–4.0 per UNOS policy. Set to 4.0 if on dialysis.
- Total Bilirubin (mg/dL)
- Total serum bilirubin in mg/dL. Minimum value of 1.0 used in formula.
- INR
- International Normalized Ratio. Minimum value of 1.0 used in formula.
- Serum Sodium (mEq/L)
- Serum sodium in mEq/L. Clamped to 125–137 for MELD-Na calculation.
- On Dialysis
- If the patient had dialysis 2 or more times in the prior week (or 24 hours of CVVHD), select Yes — creatinine is then fixed at 4.0 regardless of the lab value entered above.
What each result means
- MELD Score
- Standard MELD score (6–40) without sodium correction.
- MELD-Na Score
- MELD score with sodium correction (6–40). Used by UNOS for transplant allocation.
- Est. 3-Month Mortality (%)
- Approximate 3-month mortality based on MELD-Na score range.
- Transplant Priority (1–4)
- 1 = lower priority (MELD-Na <12), 2 = moderate (12–17), 3 = high (18–24), 4 = very high (≥25).
- Na Used in Calc (mEq/L)
- Sodium value after clamping to 125–137 range.
- Cr Used in Calc (mg/dL)
- Creatinine value after clamping (1.0–4.0) or dialysis adjustment.
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersSerum Creatinine (mg/dL) = 1, Total Bilirubin (mg/dL) = 1, INR = 1, Serum Sodium (mEq/L) = 137 = 5 input(s) provided
- Calculate MELD ScoreMELD Score = round(max(6, min(40, meldRaw)))6 = 6
- Calculate MELD-Na ScoreMELD-Na Score = round(max(6, min(40, meldNaRaw)))6 = 6
- Calculate Est. 3-Month Mortality1.9 = 1.9%
- Calculate Transplant Priority1 = 1
Figures and sources
- MELD-Na Score (sodium-adjusted Model for End-Stage Liver Disease) (2008) — Kim WR, Biggins SW, Kremers WK, Wiesner RH, Kamath PS, Benson JT, Edwards E, Therneau TM. Hyponatremia and mortality among patients on the liver-transplant waiting list. N Engl J Med. 2008;359(10):1018-1026.
Engine last updated . Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why does checking dialysis change the score even if I also enter a creatinine value?
Dialysis clears creatinine from the blood, so a dialysis patient's measured creatinine understates how impaired their kidneys actually are. UNOS policy handles this by ignoring the entered creatinine entirely once dialysis is marked yes (2 or more sessions in the prior week, or 24 hours of CVVHD) and substituting the fixed ceiling value of 4.0 mg/dL -- the same ceiling used for any non-dialysis patient whose creatinine happens to be above 4.0. That is why the Cr Used in Calc output can differ from the value you typed.
At what point does sodium actually start affecting the score?
Only once the standard MELD score (before any sodium adjustment) exceeds 11. Below or at that threshold, MELD-Na is set equal to MELD and the sodium value you entered has no effect on the result at all, even if it is quite low. This is a real feature of the OPTN formula, not a display quirk -- it reflects that the sodium correction was derived and validated specifically for the intermediate-to-high-MELD range.
Is the 3-month mortality percentage specific to MELD-Na, or does it come from somewhere else?
It's the widely-cited waitlist mortality table built from the original UNOS MELD validation cohort (roughly 1.9% for scores 6-9, rising to about 71% for scores approaching 40), which is commonly presented alongside MELD-Na for prognostic context even though it was derived from MELD rather than MELD-Na specifically. Treat it as an approximate population-level historical benchmark, not a precise individual prediction.
Does a higher MELD-Na score guarantee a patient is placed higher on the actual transplant waiting list?
Not on its own. MELD-Na drives priority within the current US liver allocation system, but actual offer sequencing also depends on distance-based acuity circles around the donor hospital, blood type compatibility, and other allocation rules -- two candidates with the same MELD-Na score in different regions or circles will not necessarily be offered an organ at the same point. The Transplant Priority output here is a simplified score-based tier for general orientation, not a prediction of list position.
What do bilirubin, INR, and creatinine actually measure?
Each lab tracks a different organ function that MELD-Na combines into one score. Bilirubin reflects how well the liver is clearing waste products from the blood -- higher levels mean worse liver clearance. INR (International Normalized Ratio) measures how long blood takes to clot, which depends on clotting factors the liver produces, so a higher INR signals reduced synthetic liver function. Creatinine measures kidney function, since advanced liver disease frequently impairs the kidneys too (hepatorenal syndrome) -- which is also why the formula caps and overrides it for dialysis patients, per the FAQ above.
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