What the four paths are deciding
The first question splits calendar age from three special cases. “General age” opens the chronological age calculator in standard mode: years, months, days, and a Y;M;D line, with no nearest-month rounding. Use it for “how old am I,” a birthday, or any form that wants the exact span. Set the target date to a testing day if the form says “age at evaluation” and you are not applying a publisher round.
“Clinical assessment” is the path that cares about format. Pearson and WISC-style forms often want nearest-month rounding. BRIGANCE screens want exact age. Super Duper materials often want Y;M;D. The wizard sends you to the page that states that convention. It does not score the test. If your battery is not listed, use the test age calculator and read methodology before you file.
“Premature baby” is corrected age or gestational age, not a prettier chronological age. Corrected age subtracts weeks born early. Post-menstrual age adds chronological weeks to gestational age at birth. Those are different blanks in a NICU note. The wizard’s links keep them apart so a 32-week birth does not get reported as if the baby had been born at term.
“A specific unit” is for forms with one box: months, days, or weeks. Completed months are not days divided by 30. Weeks are days divided by 7. Days include leap days. The granular time page explains why loose conversions disagree. After the wizard sends you onward, the dates you type stay in the browser.
The wizard does not store which button you pressed and it does not score anything. If you land on the wrong tool, use the back control or the footer. Everyday age and test age differ only in rounding and punctuation. Prematurity differs in the quantity being measured. Mixing those paths is the mistake the four buttons are there to prevent. For a side-by-side view of the clinical formats, open the comparison matrix after you know the publisher. For the subtraction written out, open how to calculate chronological age.
Birth-year questions are not one of the four buttons. A year by itself has two ages until the birthday’s month and day are known. Use born in for that search, then the full calculator once you have the date. School cutoffs are a target date, not a special formula: put the district’s cutoff in the chronological age tool. Dog age and sibling spacing are separate calculators in the header. They are not clinical modes and they are not unit conversions. Pick them from the menu when that is actually the question. If none of the buttons match, use the homepage calculator and read the methodology page before you round. Back returns to the first question. Nothing you click here is stored. The next page is where you enter dates. This page only routes you.