CDAI Calculator

A. Liquid stools
Number of liquid or soft stools over the last 7 days
sum x 2
B. Abdominal pain
Daily assesment
None = 0; Intermediate = 1 or 2; Severe = 3
sum x 5
C. General well being
Daily assesment
Well = 0; Intermediate = 1, 2 or 3; Terrible = 4
sum x 7
D. Extra-intestinal
Skin/mouth lesions
Peri-anal disease
Other fistula
Fever >37.8°C (in the last week)
score x 20
E. Anti-diarrhoeals
(eg Lomotil)
value x 30
F. Abdominal mass
None (0) Questionable (2) Definite (5)
value x 10
G. Haematocrit or PCV
Males (47-Hct) Females (42-Hct)
Current value %
value x 6
H. Weight
Maximum deduction of 10 for overweight patients as per Medicare Australia
Current value kg
100 x (1 − currentstandard)

About the calculator

CDAI scores should be calculated independantly by a qualified gastroenterologist. This page calculates Adult CDAI scores as defined by Medicare Australia for information only. This score determines eligibility for restricted drugs, including 'biologics.' Please note that there are several forms of the CDAI, and while this is the one most frequently used in Australia, it may not be consistent with other standards or calculators.


  • Enter whole positive numbers only (eg. 1 not 1.3). If unsure of a number, leave it out and add it later: the calculator will still give a partial result.
  • The Haematocrit (Hct) or Packed Cell Volume (PCV) number used in section G would have been provided after a recent blood test.
  • This is normally included in the haematology section of a "Complete Blood Picture" or "Full Blood Exam" report or similar.

Disclaimer: This website should not be used in place of medical advice, and caution should be used when reviewing any material published online through any source. Always check with your relevant medical professional before making any changes to your treatment or lifestyle.
IBD Support Australia Incorporated, NSW INC9895538, ABN 64 856 945 990