To determine the correct ASQ-3 interval for a child, you need to calculate a child's age in months and days. For easy age calculation, you can use our website [calculato][1]r at or the free ASQ Calculator app available in the Apple and Google Play app stores. A by-hand method is described on page 65 of the ASQ-3 User's...

When calculating a child's age, the developers recommend calculating in months and days, rather than weeks. Because all months except for February are longer than 4 weeks, using 4 weeks to represent a month increases a child's age artificially. For easy age calculation, you can use our [website calculator][1] or the fr...

The age calculator on the [website ][1]and in the app stores uses an actual calendar to calculate a child's age. It takes into account which months have 30 days and which months have 31 days, and therefore provides a more precise age calculation. For ease of use, the manual calculation described in the User's Guides as...

There are no gaps between age intervals for ASQ-3 and ASQ:SE-2 questionnaires so there is always a questionnaire available for children in the appropriate age ranges (1-66 months for ASQ-3 and 1-72 months for ASQ:SE-2). Even when there is not an ASQ:SE-2 questionnaire with the exact same age as an ASQ-3 questionnaire, ...