Chronological Age vs Biological Age: What is the Difference? (Calculator Included)
Chronological age is the actual time you have lived since birth, in years, months, and days. Biological age is an estimate of how old your body seems based on health markers, fitness, or lab results. For standardized testing, IEPs, and assessments, you always need chronological age, not biological age.
When to Use Chronological Age
Pearson, BRIGANCE, and other norm-referenced assessments use chronological age. Enter birth date and test date to get the exact age in years, months, and days required for scoring and eligibility.
When Biological Age Is Used
Biological age is used in research or wellness contexts (e.g., longevity, health risk). It is not used for educational or psychological test scoring. Our tool calculates chronological age only.