How to Use Crohn’s Disease Activity Index (CDAI) Calculator
Enter seven-day totals for liquid stools, abdominal pain, and general wellbeing, then add complications, antidiarrheal or opiate use, abdominal mass, hematocrit, sex, and weight percent of standard. The CDAI Calculator returns a weighted disease activity score.
The stool, pain, and wellbeing fields should represent the same seven-day diary window. Missing days can lower or distort the final score because the formula expects weekly totals.
The result is grouped into remission, mild, moderate, or severe activity ranges. Use it as a structured activity estimate, not as a substitute for endoscopy, biomarkers, imaging, or clinician assessment.
Formula & Theory — Crohn’s Disease Activity Index (CDAI) Calculator
The Crohn’s Disease Activity Index (CDAI) Calculator uses the following formula or scoring rule:
CDAI = 2S + 5P + 7W + 20C + 30D + 10M + 6H + weight termCDAI is a weighted sum. Liquid stools have a multiplier of 2, abdominal pain 5, general wellbeing 7, complications 20, antidiarrheal/opiate use 30, abdominal mass 10, hematocrit deficit 6, plus a weight term.
The hematocrit term compares the entered hematocrit with a sex-based reference. The weight term increases activity when current weight is below the standard percentage.
Because several inputs come from patient diary data, CDAI can change substantially with incomplete symptom records.
Use Cases for Crohn’s Disease Activity Index (CDAI) Calculator
The Crohn’s Disease Activity Index (CDAI) Calculator is useful in specific situations such as:
- calculating CDAI from a completed seven-day symptom diary
- teaching how different symptom domains carry different weights
- checking a clinical-trial style activity score example
- reviewing whether weight loss or hematocrit contributes strongly to the total