Academic achievement · Riverside Insights
WJ IV Age Calculator
Chronological age in years;months.days for the Woodcock-Johnson IV Tests of Cognitive Abilities and Achievement, with the published age range 2:0 – 90:0 and older checked for you.
WJ IV at a glance
| Full name | Woodcock-Johnson IV Tests of Cognitive Abilities and Achievement |
|---|---|
| Publisher | Riverside Insights |
| Published age range | 2:0 – 90:0 and older |
| Age format | Years;months.days |
| Corrected age | Not applied in standard scoring. |
| Discipline | Academic achievement |
The WJ IV covers cognitive, achievement and oral language in one co-normed system across almost the whole lifespan. Its scoring software applies its own age conventions, so verify the birth and assessment dates and use Riverside Score for standardized scores.
How the WJ IV wants the age entered
Record the birth and assessment dates accurately. The years;months.days result is a calendar-age reference; follow the WJ IV manual and Riverside Score for the age convention used in standardized scoring.
The calculator above reports calendar-age formats for reference. Enter the actual birth and assessment dates into Riverside Score, and follow the WJ IV manual for standardized scoring. The generic 15-day rounding example shown here is not a WJ IV scoring instruction.
- 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.
Worked example
A child born February 26, 2023 and assessed on September 15, 2026:
- Chronological age: 3 years, 6 months, 20 days
- Calendar-age reference: 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.
Other instruments
Same calculation, different recording format. These are the instruments most often administered alongside the WJ IV:
| Instrument | Age range | Age format |
|---|---|---|
| WIAT-4 | 4:0 – 50:11 | Years;months.days |
| KTEA-3 | 4:6 – 25:11 | Years;months.days |
| WRAT-5 | 5:0 – 85:0 and older | Years;months.days |
| WISC-V | 6:0 – 16:11 | Years;months.days |
| WPPSI-IV | 2:6 – 7:7 | Years;months.days |
| WAIS-5 | 16:0 – 90:11 | Years;months.days |
The full list is on the assessment instrument reference, and the assessment age calculator covers any instrument not listed individually.
WJ IV, Riverside Insights are trademarks of their respective owners. AgeCalc is not affiliated with, endorsed by, or sponsored by any of them. Brand names are used descriptively to identify the assessment formats this calculator supports.