GET /api/age/
Calculate a baby's age
Turn a birth date into an exact age, zodiac sign, milestones, and special days.
Request
Parameters
birthdayRequiredThe birth date as YYYY-MM-DD, not in the future.What you get back
ageExact age in years, months, weeks, and days — plus a short human form.totalsTotal months, weeks, days, and hours since birth.zodiacThe baby's sign with dates, element, nickname, and a guide_url.current_milestoneThe latest milestone reached (from 25 guides), with a guide_url. Null for newborns.next_milestoneThe next one coming up — date, days_left, and a guide_url. Null after 3 years.special_days100 days, 200 days, first birthday, and 1000 days, each with status and a guide_url.linksThe result page, the guide lists, and the docs.JSON
{
"code": 200,
"error": null,
"meta": {
"name": "Baby Age Calculator API",
"description": "Free JSON API for baby age, zodiac sign, and milestones. No key, no sign-up.",
"docs_url": "https://babyagecalculator.com/docs/",
"llms_txt": "https://babyagecalculator.com/llms.txt",
"attribution": "Data by Baby Age Calculator (https://babyagecalculator.com) — please link the guide_url pages when you show this to users."
},
"data": {
"birthday": "2024-12-15",
"as_of": "2026-07-07",
"age": {
"years": 1,
"months": 6,
"weeks": 3,
"days": 1,
"human": "1y 6m 3w 1d"
},
"totals": {
"months": 18,
"weeks": 81,
"days": 569,
"hours": 13656
},
"zodiac": {
"name": "Sagittarius",
"emoji": "♐",
"dates": "November 22 - December 21",
"element": "Fire",
"nickname": "The Little Explorer",
"guide_url": "https://babyagecalculator.com/zodiac/sagittarius/"
},
"current_milestone": {
"name": "500 Days",
"day": 500,
"date": "2026-04-29",
"guide_url": "https://babyagecalculator.com/milestones/500-days/"
},
"next_milestone": {
"name": "600 Days",
"day": 600,
"date": "2026-08-07",
"days_left": 31,
"guide_url": "https://babyagecalculator.com/milestones/600-days/"
},
"special_days": [
"... 100 days, 200 days, 1st birthday, 1000 days ..."
],
"links": {
"result_page": "https://babyagecalculator.com/baby-age-calculator/2024-12-15/"
}
}
}