The Revised King's score for liver transplantation in Wilson's disease is a calculator designed to evaluate the need for liver transplantation based on five clinical parameters drawn from lab tests: bilirubin levels, international normalized ratio (INR), aspartate aminotransferase (AST), white cell count, and albumin levels.

The assessment involves receiving input in the form of categorical choices for each parameter. Each choice corresponds to a specific score, and these scores are summed to yield a total score. Here is how scoring is done:

1. Bilirubin, mcol/L:
   - 0-100: 0 points
   - 101-150: 1 point
   - 151-200: 2 points
   - 201-300: 3 points
   - > 301: 4 points

2. International normalized ratio:
   - 0-1.29: 0 points
   - 1.3-1.6: 1 point
   - 1.7-1.9: 2 points
   - 2.0-2.4: 3 points
   - > 2.5: 4 points

3. Aspartate aminotransferase, IU/L:
   - 0-100: 0 points
   - 101-150: 1 point
   - 151-300: 2 points
   - 301-400: 3 points
   - > 401: 4 points

4. White cell count, 10^9/L:
   - 0-6.7: 0 points
   - 6.8-8.3: 1 point
   - 8.4-10.3: 2 points
   - 10.4-15.3: 3 points
   - > 15.4: 4 points

5. Albumin, g/L:
   - > 45: 0 points
   - 34-44: 1 point
   - 25-33: 2 points
   - 21-24: 3 points
   - < 20: 4 points

The total score can range from 0 to 20. The interpretation of the total score is as follows:

- Scores between 0 and 10 predict a successful response to chelation therapy, suggesting that liver transplantation is not immediately necessary.
- Scores from 11 to 20 indicate a need for liver transplantation.

The Revised King's Score is a clinical calculator used specifically for patients with Wilson's disease, a rare inherited disorder that causes copper to accumulate in the liver, brain, and other vital organs. This scoring system is used to determine the necessity and urgency of liver transplantation in these patients. 

The Revised King's Score takes into account various clinical parameters such as bilirubin, albumin, prothrombin time, and presence of neurological symptoms. The higher the score, the greater the need for urgent liver transplantation. 

This calculator is not applicable to patients without Wilson's disease or those with Wilson's disease who do not have liver involvement. It is also not suitable for patients with other causes of liver disease or those who have contraindications to liver transplantation.