Developmental & early childhood · Denver Developmental Materials
Denver II Age Calculator
Chronological age in years;months.days for the Denver Developmental Screening Test II, with the published age range Birth – 6:0 checked for you.
Denver II at a glance
| Full name | Denver Developmental Screening Test II |
|---|---|
| Publisher | Denver Developmental Materials |
| Published age range | Birth – 6:0 |
| Age format | Years;months.days |
| Corrected age | For children born more than 2 weeks preterm, the age line is drawn from the corrected age until 24 months. |
| Discipline | Developmental & early childhood |
The Denver II is a long-standing developmental screening test scored by drawing a vertical age line across four sectors of items. It is one of the few instruments where the practitioner physically constructs the score from the computed age.
How the Denver II wants the age entered
Compute the exact chronological age in years;months.days and draw the age line on the form from it. The age line is the whole scoring mechanism, so the day component is used directly.
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 Denver II manual asks for without recalculating:
- Years;months.days — the full record-form format, e.g. 1;6.20
- Years;months — complete units only, e.g. 1;6
- Complete months — e.g. 18 months
- Rounded to nearest month — e.g. 19 months (1;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, 2025 and assessed on September 15, 2026:
- Chronological age: 1 year, 6 months, 20 days
- Record on the Denver II as: 1;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.
Corrected age and the Denver II
For children born more than 2 weeks preterm, the age line is drawn from the corrected age until 24 months.
Corrected (adjusted) age is measured from the due date rather than the birth date. Switch the calculator above to Born preterm and enter the gestational age at birth to see both figures side by side. The dedicated adjusted age calculator adds gestational and postmenstrual age, and the corrected age guide explains the convention for families.
Other instruments
Same calculation, different recording format. These are the instruments most often administered alongside the Denver II:
| Instrument | Age range | Age format |
|---|---|---|
| Bayley-4 | 16 days – 42 months | Years;months.days |
| Mullen | Birth – 68 months | Years;months.days |
| DAYC-2 | Birth – 5:11 | Total months |
| BDI-3 | Birth – 7:11 | Total months |
| ASQ-3 | 1 – 66 months | Total months |
| ASQ:SE-2 | 1 – 72 months | Total months |
The full list is on the assessment instrument reference, and the assessment age calculator covers any instrument not listed individually.
Denver II, Denver Developmental Materials 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.