With the recent acceptance of multiple treatment goals for inflammatory bowel diseases (IBD), it becomes increasingly important to accurately quantify the measurable concepts. These include patient-reported symptoms, intestinal damage, mucosal activity, transmural inflammation, and histologic appearance, as well as quality of life, disability, and other patient-centered attributes. Standardized indices which show sufficient validity, reliability, and responsiveness to change are not only mandatory for implementing the treat-to-target approach but are also critical for assessing the effectiveness of emerging medications in clinical trial settings. Some concepts can be accurately assessed through the use of existing measurement tools used for adults (e.g. capsule endoscopy, ultrasonic, endoscopic, and histologic scoring) while others may be age-specific. Although several pediatric indices and scales are well established (e.g. IMPACT questionnaire, PCDAI, and PUCAI), recent years have seen the development of newer indices for children, including the MINI to predict endoscopic healing in Crohn's disease, MRI indices that measure inflammation (i.e. PICMI) and perianal disease (i.e. PEMPAC), and patient-reported outcome measures in ulcerative colitis (i.e. TUMMY-UC), upper gastrointestinal inflammatory score (i.e. UGI-SES-CD), simplified endoscopic mucosal assessment score for Crohn's disease (SEMA-CD), and the parent-completed IMPACT questionnaire (i.e. IMPACT-III-P). Despite these advances, quantifiable pediatric IBD-specific tools are still lacking for disability and fatigue. In this review, we provide a contemporary, clinically-focused overview of the indices that a pediatric gastroenterologist can use to quantify disease status.