SB5 Age Calculator

The SB5 spans early childhood to late adulthood in a single battery and is often chosen when an evaluation needs a wide age range or extended low-end floor. Routing tests set the entry point for each subsequent subtest, and chronological age is what fixes the starting level.

Enter the exact chronological age in years;months.days. Scoring selects the norm table containing that age, so the partial month is not rounded up.

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 SB5 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 SB5 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 SB5:

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