Enter the number of days covered and the total number of days into the Proportion of Days Covered Calculator. The calculator will evaluate the Proportion of Days Covered. 

Proportion of Days Covered Calculator

Enter any 2 values to calculate the missing variable

Note: If Days Covered exceeds Total Days, PDC is typically capped at 100% in many quality measures.

Note: This calculator is for informational/quality-measurement purposes only and is not medical advice. Do not start, stop, or change how you take any medication based on these results—talk to your prescriber or pharmacist. PDC may not reflect true adherence (e.g., dose changes, “as needed” use, samples, hospital stays, switching medications), and thresholds (like 80%) vary by program and medication.

Proportion of Days Covered Formula

The following two example problems outline the steps and information needed to calculate the Proportion of Days Covered.

PDC = DC / D * 100

Variables:

  • PDC (%) is the Proportion of Days Covered
  • DC is the number of days covered 
  • D is the total number of days in the period 

To calculate the proportion of days covered, divide the number of days covered by the total number of days, then multiply by 100.

How to Calculate Proportion of Days Covered?

The following steps outline how to calculate the Proportion of Days Covered.

  1. First, determine the number of days covered. 
  2. Next, determine the total number of days. 
  3. Next, gather the formula from above: PDC = DC / D * 100.
  4. Finally, calculate the Proportion of Days Covered.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

number of days covered = 576

total number of days = 1000

PDC = DC / D * 100 = ?