MELD-Na Calculator
Enter the latest lab values to estimate MELD and MELD-Na scores for adults with chronic liver disease.
Sodium is bounded to 125–137 for MELD-Na calculation.
What is the MELD-Na score?
MELD-Na is a clinical scoring system used to estimate disease severity in people with advanced liver disease. It builds on the original MELD score by incorporating serum sodium, which improves risk prediction in many patients. In transplant medicine, MELD-Na helps prioritize liver transplant waitlist allocation.
Inputs used in this calculator
- Bilirubin: reflects liver excretory function.
- INR: reflects blood clotting function and synthetic liver performance.
- Creatinine: reflects kidney function, an important driver of prognosis.
- Sodium: low sodium (hyponatremia) is linked with poorer outcomes in cirrhosis.
- Recent dialysis status: if true, creatinine is set to 4.0 in standard MELD calculations.
How the MELD-Na formula works
Step 1: Compute MELD
The calculator uses the classic MELD equation:
MELD = 10 × (0.957 × ln(creatinine) + 0.378 × ln(bilirubin) + 1.12 × ln(INR) + 0.643)
Practical bounds are applied:
- Bilirubin, INR, and creatinine are floored at 1.0 for the logarithmic term.
- Creatinine is capped at 4.0 (or set to 4.0 if recent dialysis criteria are met).
- MELD is then constrained to 6–40.
Step 2: Add sodium adjustment
Sodium is bounded to 125–137 mEq/L, then:
MELD-Na = MELD + 1.32 × (137 − Na) − [0.033 × MELD × (137 − Na)]
Final MELD-Na is rounded and constrained to 6–40.
Quick interpretation guide (educational)
| MELD-Na Range | General Risk Signal |
|---|---|
| 6–9 | Lower short-term risk compared with higher categories |
| 10–19 | Moderate disease severity; close follow-up is important |
| 20–29 | High severity; urgent specialist management often needed |
| 30–39 | Very high severity; significant short-term mortality risk |
| 40 | Extreme severity category |
Important limitations
- This tool is for informational and educational use only.
- Lab timing, acute illness, and treatment context can change clinical meaning.
- MELD-Na is not a standalone diagnosis and should not replace physician judgment.
- Transplant programs may use additional criteria and policy-specific rules.
Frequently asked questions
Does a higher MELD-Na always mean immediate transplant?
Not always. A higher score generally indicates greater urgency, but transplant eligibility depends on many clinical and logistical factors.
Can I use old lab values?
For meaningful estimates, use the most recent verified laboratory values. Outdated data can produce misleading results.
What if sodium is outside normal range?
The formula uses sodium bounded between 125 and 137 mEq/L by convention, which this calculator automatically applies.
Medical disclaimer: This page does not provide medical advice, diagnosis, or treatment. Always consult a qualified clinician for personal care decisions.