GFTA-3 Age Calculator

The GFTA-3 is the default single-word articulation measure in school-based caseloads and is often the sole standardized measure behind a speech-sound eligibility. It is co-normed with the KLPA-3 for phonological process analysis.

Enter the exact chronological age in years;months.days. Articulation norms move quickly in the preschool years, so the norm bands at the low end are narrow.

The underlying calculation is the same for every instrument — complete years, complete months, then the leftover days. What differs is which part of it goes on the form. The calculator above reports all four figures at once, so you can copy the one the GFTA-3 manual asks for without recalculating:

• Years;months.days — the full record-form format, e.g. 3;6.20
• Years;months — complete units only, e.g. 3;6
• Complete months — e.g. 42 months
• Rounded to nearest month — e.g. 43 months (3;7), using the 15-day threshold

The exact date arithmetic, including month-end clamping and leap-day handling, is documented in the calculation methodology.

A child born February 26, 2023 and assessed on September 15, 2026:

• Chronological age: 3 years, 6 months, 20 days
• Record on the GFTA-3 as: 3;6.20
• Day remainder: 20 days — 15 or more, so a nearest-month rounding rounds up

Enter these exact dates above to reproduce the result. Every figure on this page is computed by the same library that runs the calculator, so the worked example and the tool can never disagree.

Same calculation, different recording format. These are the instruments most often administered alongside the GFTA-3:

The full list is on the assessment instrument reference, and the assessment age calculator covers any instrument not listed individually.