Crohn's Disease Activity Index (CDAI)

Enter 8 clinical variables over the past 7 days to calculate your CDAI score and determine Crohn's disease activity level.

Enter 7-Day Clinical Variables

Record values from the past 7 consecutive days. All fields are required for an accurate CDAI score.

Count every loose or liquid stool over the past 7 days. Weight factor: ×2

Rate each day: 0 = none, 1 = mild, 2 = moderate, 3 = severe. Enter the 7-day sum (0-21). Weight factor: ×5

Rate each day: 0 = generally well, 1 = slightly below par, 2 = poor, 3 = very poor, 4 = terrible. Enter the 7-day sum (0-28). Weight factor: ×7

Check each complication currently present. Each item adds 1 point × 20. Weight factor: ×20 per item

Used loperamide, opiates, or similar antidiarrheals in the past 7 days? Weight factor: ×30

Assessed by a clinician on physical examination. Weight factor: ×10

The calculator uses the expected normal (47% for men, 42% for women). Weight factor: ×6 on the deviation.

Enter standard weight and current weight. Weight factor: ×1 on percent deviation below standard (negative values enter as 0).

Fill in all variables and press
Calculate CDAI Score

CDAI Classification

Score Range Activity Level
< 150Remission
150 – 219Mildly Active
220 – 450Moderately Active
> 450Severely Active
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Summary

Enter 8 clinical variables over the past 7 days to calculate your CDAI score and determine Crohn's disease activity level.

How it works

  1. Record each of the 8 clinical variables over the past 7 consecutive days.
  2. Enter the 7-day totals or select the appropriate category for each variable.
  3. The calculator multiplies each variable by its predefined weighting factor.
  4. All weighted values are summed to produce the total CDAI score.
  5. The score is classified as remission (<150), mild (150-219), moderate (220-450), or severe (>450).
  6. Use the result alongside your physician's clinical assessment to guide treatment decisions.

Use cases

  • Monitor disease activity trends over time in Crohn's patients.
  • Assess eligibility for clinical trials requiring a baseline CDAI score.
  • Evaluate response to biologic or immunosuppressive therapy.
  • Determine whether a patient meets the threshold for clinical remission.
  • Guide shared decision-making between patients and gastroenterologists.
  • Standardize disease activity reporting across care teams.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu