Calculate the Child-Pugh score from bilirubin, albumin, INR, ascites, and encephalopathy to grade cirrhosis severity as Class A, B, or C.
Child-Pugh Score Formula
The Child-Pugh score adds five point values, each scored from 1 to 3, into a single total from 5 to 15.
Child-Pugh Score = B + A + I + As + E
- B = total bilirubin points (1 to 3)
- A = serum albumin points (1 to 3)
- I = INR (or prothrombin time) points (1 to 3)
- As = ascites points (1 to 3)
- E = hepatic encephalopathy points (1 to 3)
Each of the five parameters is graded 1, 2, or 3 based on how abnormal it is, and the five point values are summed. A higher bilirubin, a lower albumin, a higher INR, more ascites, or worse encephalopathy each pushes a parameter toward 3 points. The total maps to a class: 5 to 6 is Class A, 7 to 9 is Class B, and 10 to 15 is Class C.
The calculator gives you two ways to reach that total. In lab-value mode you type the measured bilirubin, albumin, and INR, and the tool assigns each point value using the thresholds below, so you do not have to look up which band a value falls in. If your lab reports prothrombin time as seconds prolonged above control instead of INR, switch the coagulation measure and the same 1 to 3 scoring applies. In category mode you pick the point band for each parameter directly. Ascites and encephalopathy are always graded by category because they are clinical findings rather than lab numbers. After it totals the score, the calculator also reports the margin to the next class, meaning how many points separate the current score from the Class B or Class C threshold.
Child-Pugh Scoring Criteria and Class Interpretation
The point thresholds are shown in both conventional (US) units and SI units, with the prothrombin time alternative for the coagulation row.
| Measure | 1 point | 2 points | 3 points |
|---|---|---|---|
| Bilirubin (mg/dL) | Under 2 | 2 to 3 | Over 3 |
| Bilirubin (µmol/L) | Under 34 | 34 to 51 | Over 51 |
| Albumin (g/dL) | Over 3.5 | 2.8 to 3.5 | Under 2.8 |
| Albumin (g/L) | Over 35 | 28 to 35 | Under 28 |
| INR | Under 1.7 | 1.7 to 2.3 | Over 2.3 |
| PT prolongation (seconds) | Under 4 | 4 to 6 | Over 6 |
| Ascites | None | Slight or mild | Moderate to severe |
| Encephalopathy | None | Grade 1 to 2 | Grade 3 to 4 |
The total score corresponds to a class, and each class carries a broad prognosis. The survival and surgical figures below come from published cirrhosis cohorts and are approximate; they vary with the cause of liver disease, treatment, and other conditions.
| Score | Class | Meaning | 1-year survival | 2-year survival | Abdominal surgery mortality |
|---|---|---|---|---|---|
| 5 to 6 | A | Compensated | About 100% | About 85% | About 10% |
| 7 to 9 | B | Significant compromise | About 80% | About 60% | About 30% |
| 10 to 15 | C | Decompensated | About 45% | About 35% | About 70 to 80% |
The class is also used in drug labeling. Product information for many medicines refers to Child-Pugh A, B, or C when setting dose reductions or cautions, and some drugs are not recommended in Class C. This is why the score is calculated outside of surgery and transplant settings, for example when deciding how to dose a medicine that is cleared by the liver.
Example Problems
Example 1. A patient has a total bilirubin of 2.5 mg/dL, albumin of 3.0 g/dL, INR of 1.9, slight ascites, and no encephalopathy. Bilirubin scores 2, albumin scores 2, INR scores 2, ascites scores 2, and encephalopathy scores 1. The total is 2 + 2 + 2 + 2 + 1 = 9, which is Class B, one point below the Class C threshold.
Example 2. A patient has a total bilirubin of 4.5 mg/dL, albumin of 2.5 g/dL, INR of 2.6, moderate ascites, and grade 3 encephalopathy. Each parameter scores 3, so the total is 3 + 3 + 3 + 3 + 3 = 15, the maximum, which is Class C.
Frequently Asked Questions
What is a good Child-Pugh score? The lowest possible score is 5, which is Class A and reflects well-compensated liver function. Scores of 5 to 6 carry the best prognosis. A score of 7 to 9 is Class B and signals meaningful loss of function, while 10 to 15 is Class C and indicates decompensated cirrhosis. Lower is better, and a score that rises over time points to worsening disease.
How is the Child-Pugh score different from MELD? Both estimate the severity of chronic liver disease, but they use different inputs. The Child-Pugh score combines three lab values with two clinical findings, ascites and encephalopathy, that depend on examiner judgment. MELD and MELD-Na use only objective lab values, such as bilirubin, creatinine, INR, and sodium, and produce a continuous number rather than three classes. MELD is used to rank patients for liver transplant, while Child-Pugh remains common for general prognosis and for drug dosing decisions.
Can the Child-Pugh class change? Yes. The score reflects the patient’s current state, so it should be recalculated when the clinical picture changes. Treating ascites or encephalopathy, or an improvement in bilirubin, albumin, or INR, can lower the score and move a patient from Class C to B or from B to A. The reverse is also true, which is why the margin to the next class is worth watching in patients who are trending toward decompensation.