About MELD Score Calculator
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MELD Score Calculator: Estimate Liver Disease Severity, Transplant Priority, and Mortality Risk
TL;DR: Four lab values produce two scores that determine how urgently you need a liver transplant. A MELD below 10 carries roughly 2% three-month mortality; a MELD of 40 or above pushes that figure past 71%. The MELD-Na adjustment, which factors in serum sodium, improves prediction accuracy for patients with cirrhosis and hyponatremia. Enter your lab results above to get both scores instantly.
Table of Contents
- Why Four Lab Values Decide Your Place on the Transplant List
- Six Clinical Situations Where This Calculator Matters
- The MELD and MELD-Na Formulas Explained
- How to Use This Calculator: Step by Step
- Putting the Formulas to Work: Two Worked Examples
- Six Errors That Distort Your MELD Result
- FAQ
- Assumptions and Notes
- What to Do After You Get Your Score
- Further Reading
Why Four Lab Values Decide Your Place on the Transplant List
Every day, roughly 17 people are added to the liver transplant waiting list in the United States, and about 3 of those will die or become too sick for surgery before an organ becomes available. The question that governs who receives a donor liver first is not who has waited longest. Since 2002, it has been who is most likely to die without one.
The Model for End-Stage Liver Disease (MELD) score answers that question with a number derived from three objective lab measurements: serum bilirubin (a marker of the liver's ability to process waste), the international normalised ratio or INR (a measure of the liver's role in blood clotting), and serum creatinine (reflecting kidney function, which deteriorates as liver failure progresses). The original formula was published by Kamath et al. in 2001 and adopted by UNOS for organ allocation in February 2002, replacing the older Child-Turcotte-Pugh system that relied partly on subjective clinical assessments.
In 2016, UNOS adopted the MELD-Na modification, which incorporates serum sodium into the calculation. Hyponatremia (low sodium) is an independent predictor of mortality in cirrhosis patients because it reflects the severity of portal hypertension and fluid retention. Patients with identical MELD scores but different sodium levels can have meaningfully different survival probabilities. Genetic variation in sodium handling, particularly polymorphisms affecting the renin-angiotensin-aldosterone system, contributes to why two patients with similar liver damage can present with different sodium levels and therefore different MELD-Na scores.
The calculator above returns both scores from your lab values in under ten seconds.
Six Clinical Situations Where This Calculator Matters
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You have cirrhosis and want to understand your prognosis. A MELD score below 10 corresponds to approximately 2% three-month mortality, while a score between 20 and 29 raises that estimate to about 20%. Knowing where you fall on this scale gives you a concrete frame for conversations with your hepatologist about treatment intensity and monitoring frequency.
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You are being evaluated for liver transplant listing. UNOS uses the MELD-Na score as the primary allocation metric. Patients with a MELD-Na of 15 or higher are generally considered transplant candidates, and those above 25 receive increasing priority. Calculating your score before your transplant evaluation appointment lets you anticipate the clinical team's assessment and prepare informed questions.
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Your doctor is deciding how often to recheck your labs. UNOS requires MELD recertification at intervals tied to the score itself: every 12 months for scores below 11, every 3 months for 11 to 18, monthly for 19 to 24, and weekly for 25 and above. Knowing your current score tells you when your next recertification is due.
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You are on dialysis or have had recent renal replacement therapy. The MELD formula sets creatinine to 4.0 mg/dL for patients who have received dialysis at least twice in the past week or who are on continuous venovenous hemofiltration (CVVHD). This adjustment can raise a MELD score by 8 to 15 points compared to the patient's actual creatinine value, substantially changing transplant priority.
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Your sodium has been trending downward. A serum sodium drop from 137 to 128 mEq/L can add 6 to 10 points to the MELD-Na score compared to the base MELD. Tracking MELD-Na alongside standard MELD helps you and your care team detect worsening portal hypertension before it manifests as overt clinical decompensation.
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You are comparing treatment options for hepatic decompensation. Interventions like transjugular intrahepatic portosystemic shunt (TIPS) placement can worsen liver function in some patients. Running the MELD calculation before and after a procedure provides a quantitative measure of whether the intervention improved or worsened overall hepatic status. A post-procedure MELD increase of more than 5 points is a red flag that warrants urgent reassessment.
The MELD and MELD-Na Formulas Explained
The MELD score uses three lab values in a logarithmic equation that weights each variable according to its independent contribution to 90-day mortality risk.
MELD = 10 x (0.957 x ln(Creatinine) + 0.378 x ln(Bilirubin) + 1.120 x ln(INR) + 0.643)
Rules:
- All lab values below 1.0 are set to 1.0 before calculation
- Creatinine is capped at 4.0 mg/dL
- If the patient has received dialysis >= 2 times/week or CVVHD: Creatinine = 4.0
MELD-Na = MELD + 1.32 x (137 - Na) - 0.033 x MELD x (137 - Na)
Rules:
- Sodium is clamped to the range 125-137 mEq/L
- If Na >= 137, MELD-Na equals MELD (no sodium adjustment)
- If Na <= 125, Na is set to 125 for the calculation
MELD Score and 3-Month Mortality
| MELD Score | 3-Month Mortality | Clinical Interpretation |
|---|---|---|
| Below 10 | ~2% | Low short-term risk |
| 10 to 19 | ~6% | Moderate risk, monitoring required |
| 20 to 29 | ~20% | High risk, transplant evaluation indicated |
| 30 to 39 | ~53% | Very high risk, urgent transplant need |
| 40 or above | ~71% | Critical, highest transplant priority |
UNOS MELD Recertification Schedule
| MELD Score | Recertification Interval |
|---|---|
| Below 11 | Every 12 months |
| 11 to 18 | Every 3 months |
| 19 to 24 | Every 1 month |
| 25 and above | Every 7 days |
Limitations. The MELD formula was derived from a population of patients undergoing TIPS procedures and later validated for broader liver disease populations. It does not account for certain conditions that affect transplant urgency independently, including hepatocellular carcinoma (which receives MELD exception points), hepatopulmonary syndrome, or primary non-function of a prior graft. These conditions use separate UNOS exception pathways.
How to Use This Calculator: Step by Step
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Gather your most recent lab results. You need serum bilirubin (mg/dL), INR, serum creatinine (mg/dL), and serum sodium (mEq/L). Labs should ideally be from the same blood draw, taken within the past 48 hours for clinical relevance.
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Enter your bilirubin value. Normal range is 0.1 to 1.2 mg/dL. Values in advanced cirrhosis commonly range from 2 to 30 mg/dL. The calculator sets any value below 1.0 to 1.0 per the original MELD convention.
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Enter your INR. Normal INR is around 1.0 for patients not on anticoagulants. In liver failure, INR commonly rises to 1.5 to 3.0 or higher because the liver produces most clotting factors. Note that warfarin therapy will artificially raise INR and inflate the MELD score.
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Enter your creatinine. Normal is 0.7 to 1.3 mg/dL. If you have received dialysis two or more times in the past seven days, select "Yes" for the dialysis question, and the calculator will automatically set creatinine to 4.0 mg/dL.
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Enter your sodium. Normal range is 136 to 145 mEq/L. The formula clamps sodium to the 125 to 137 range. Values above 137 produce no sodium adjustment. Values below 125 are treated as 125.
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Select your dialysis status. This single toggle can shift your MELD score dramatically. Be accurate: the adjustment applies only if you have had two or more dialysis sessions in the preceding week or are on CVVHD.
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Read your results. The calculator returns three outputs: the base MELD score (Kamath et al., 2001), the MELD-Na score, and a text-based prognosis estimate. Compare your MELD-Na to the mortality table above for context. One non-obvious detail: a MELD and MELD-Na that are nearly identical indicate your sodium is close to 137, meaning hyponatremia is not currently contributing to your risk profile.
Putting the Formulas to Work: Two Worked Examples
Example 1: 58-Year-Old Man with Alcoholic Cirrhosis
A 58-year-old man with a 20-year history of alcohol use disorder presents with jaundice and ascites. His labs show bilirubin 4.8 mg/dL, INR 1.9, creatinine 1.4 mg/dL, and sodium 131 mEq/L. He is not on dialysis.
Step 1: Calculate base MELD
MELD = 10 x (0.957 x ln(1.4) + 0.378 x ln(4.8) + 1.120 x ln(1.9) + 0.643)
= 10 x (0.957 x 0.3365 + 0.378 x 1.5686 + 1.120 x 0.6419 + 0.643)
= 10 x (0.3220 + 0.5929 + 0.7189 + 0.643)
= 10 x 2.2768
= 22.8 (rounded to 23)
Step 2: Calculate MELD-Na (Na = 131, clamped within 125-137)
MELD-Na = 23 + 1.32 x (137 - 131) - 0.033 x 23 x (137 - 131)
= 23 + 1.32 x 6 - 0.033 x 23 x 6
= 23 + 7.92 - 4.554
= 26.4 (rounded to 26)
| Parameter | Value | Notes |
|---|---|---|
| MELD Score | 23 | 20-29 range: ~20% three-month mortality |
| MELD-Na Score | 26 | Sodium adjustment added 3 points |
| Prognosis | High risk | Transplant evaluation strongly indicated |
What this means for him: His base MELD of 23 places him in the high-risk category, and the sodium correction pushes his MELD-Na to 26. At this score, UNOS requires weekly recertification labs. His hepatologist should initiate a formal transplant evaluation if one has not already begun. The 3-point gap between MELD and MELD-Na signals that hyponatremia is contributing meaningfully to his risk.
Example 2: 44-Year-Old Woman with Autoimmune Hepatitis on Dialysis
A 44-year-old woman with autoimmune hepatitis and hepatorenal syndrome has been receiving hemodialysis three times per week for the past two weeks. Her labs: bilirubin 8.2 mg/dL, INR 2.4, creatinine 3.1 mg/dL (but dialysis override applies), sodium 126 mEq/L.
Step 1: Dialysis adjustment sets creatinine to 4.0
Step 2: Calculate base MELD
MELD = 10 x (0.957 x ln(4.0) + 0.378 x ln(8.2) + 1.120 x ln(2.4) + 0.643)
= 10 x (0.957 x 1.3863 + 0.378 x 2.1041 + 1.120 x 0.8755 + 0.643)
= 10 x (1.3267 + 0.7954 + 0.9806 + 0.643)
= 10 x 3.7457
= 37.5 (rounded to 38)
Step 3: Calculate MELD-Na (Na = 126, clamped within 125-137)
MELD-Na = 38 + 1.32 x (137 - 126) - 0.033 x 38 x (137 - 126)
= 38 + 1.32 x 11 - 0.033 x 38 x 11
= 38 + 14.52 - 13.794
= 38.7 (rounded to 39)
| Parameter | Value | Notes |
|---|---|---|
| MELD Score | 38 | 30-39 range: ~53% three-month mortality |
| MELD-Na Score | 39 | Near the critical 40 threshold |
| Prognosis | Very high risk | Highest transplant priority tier approaching |
What this means for her: The dialysis adjustment raised her creatinine from 3.1 to 4.0, pushing the MELD score significantly higher than it would be using her actual creatinine (which would yield a MELD of approximately 33). Her MELD-Na of 39 places her one point below the 40 threshold where three-month mortality exceeds 71%. She is in the very high priority range for organ allocation.
Six Errors That Distort Your MELD Result
Using lab values from different dates. Bilirubin, INR, and creatinine can shift by 20 to 40% within 48 hours during acute decompensation. Mixing a creatinine from Monday with an INR from Friday produces a score that reflects neither day accurately. Use values from a single blood draw whenever possible.
Forgetting to select the dialysis adjustment. The difference between an actual creatinine of 1.8 and the dialysis-adjusted value of 4.0 can change a MELD score by 10 or more points. If you have had two or more dialysis sessions in the past week and do not apply the adjustment, your calculated score will substantially underestimate your transplant priority.
Entering bilirubin in SI units instead of conventional units. Bilirubin in micromol/L (the standard in many countries outside the US) produces values roughly 17 times higher than mg/dL. Entering 82 micromol/L instead of the equivalent 4.8 mg/dL will generate a wildly inflated MELD score. Divide micromol/L by 17.1 to convert before entering.
Ignoring the effect of warfarin on INR. Patients taking warfarin for indications unrelated to liver disease (such as atrial fibrillation or mechanical heart valves) will have elevated INR values that inflate the MELD score artificially. The INR elevation in these cases reflects anticoagulant effect, not hepatic synthetic dysfunction. UNOS has specific policies for INR adjustment in anticoagulated patients; ask your transplant centre about their protocol.
Assuming MELD alone determines transplant listing. MELD-Na is the allocation score used by UNOS since January 2016. A patient with a MELD of 22 and sodium of 126 has a MELD-Na of approximately 28, a meaningful difference in transplant queue position. Always calculate MELD-Na alongside the base score for an accurate picture of allocation priority.
Treating the score as static between lab draws. Liver disease can progress rapidly. A MELD of 18 measured six weeks ago may be 25 today if bilirubin or creatinine has risen. For scores above 19, UNOS requires monthly or weekly recertification precisely because the score can shift fast enough to change clinical decisions within days.
Assumptions and Notes
- Margin of error. The MELD score has a concordance statistic (c-statistic) of approximately 0.83 to 0.87 for predicting three-month mortality in validation studies. Individual predictions carry uncertainty, and two patients with the same score can have different outcomes based on factors the formula does not capture.
- Professional disclaimer. This calculator is an educational tool. MELD and MELD-Na scores used for transplant allocation are calculated by UNOS-certified transplant centres using verified lab results. Do not use this calculator as a substitute for clinical evaluation by a hepatologist or transplant team. Treatment decisions, including transplant listing and anticoagulation management, require professional medical judgment.
What to Do After You Get Your Score
The 58-year-old man from Example 1 walked into his appointment thinking cirrhosis was a slow disease. His MELD-Na of 26 told him and his doctor that the next three months carry real risk, and that transplant evaluation should start now rather than at the next quarterly visit.
Print your results. Bring them to your hepatologist. Ask where you stand.