Chronological Age Calculator in Months

Calculate exact age in months for educational and clinical assessments

Birth Date

Test/Assessment Date

Why Calculate Age in Months?

Speech-language pathologists (SLPs), special education teachers, and psychologists frequently need chronological age expressed in months for standardized assessments. Child development changes rapidly, especially in early years, making months a more precise unit than years alone.

This calculator is specifically designed for professionals who need to calculate age for Pearson assessments, Brigance evaluations, Gesell developmental schedules, and other standardized tests that require the years;months format.

The Years;Months Format Explained

The years;months format (e.g., 6;4 for 6 years, 4 months) is standard in educational and clinical testing. The semicolon separates years from months, making it compact and unambiguous. This format is used in assessments like:

WISC-V (Wechsler Intelligence Scale for Children)
CELF-5 (Clinical Evaluation of Language Fundamentals)
PPVT-4 (Peabody Picture Vocabulary Test)
Brigance IED III and Screens

Frequently Asked Questions

Educational assessments use age in months because child development varies significantly even within a single year. A 5-year-old at 60 months has very different abilities than one at 71 months. Using months provides more precise age groupings for accurate norm comparisons and identifies smaller developmental differences.

The most common format is years;months (e.g., 6;4 for 6 years, 4 months) or sometimes years:months with a colon. Some assessments also use total months (e.g., 76 months). Always check your specific assessment manual for the required format.

For speech therapy, calculate the difference between the test date and birth date. Express the result in the years;months format. Round down partial months—if a child is 4 years, 3 months, and 15 days old, record it as 4;3. This is the standard practice for most speech-language assessments.

The 6;4 notation means 6 years and 4 months. The semicolon separates years from months. This format is standard in educational and clinical testing because it's compact and unambiguous. It's used in assessments like the WISC, WAIS, CELF, and many others.

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