Age in Years, Months, and Days
Ideal for legal paperwork, HR compliance, medical assessments, and curiosity about exact age.
Defaults to now. Change it to compare against any date.
Birth: 1/1/1990, 12:00:00 AM
Reference: 11/25/2025, 11:49:00 AM
Age: 35 year(s), 10 month(s), 24 day(s)
Additional time: 11 hour(s), 49 minute(s), 0 second(s)
Total days: 13112 day(s)
How to Use This Calculator
Set the birth timestamp
Include the exact time if available for precise output.
Select the comparison date
Use today or any target date to measure age.
Record the breakdown
Copy the years/months/days (plus time) into your forms or reports.
Formula
1. Subtract years, months, days with calendar adjustments
2. Subtract remaining hours, minutes, seconds from the residual
3. Total days = (Reference − Birth) ÷ 86,400,000
Example: 1990-01-01 08:30 → 2025-11-09 15:45 = 35y 10m 8d 7h 15m 0s → 13,145 total days.
Why Precise Age Matters
- Legal requirements (retirement, pension, immigration).
- Medical guidance where age thresholds matter.
- Academic grade placement based on cut-off dates.
- Personal curiosity and milestone celebrations.
Frequently Asked Questions
Do leap years affect the result?
Yes—the calendar subtraction handles leap years and varying month lengths automatically.
Why include hours, minutes, and seconds?
Some use cases (like neonatal care or legal filings) require exact durations, not just dates.
Can I omit the time of day?
Set both timestamps to midnight to focus on whole days.
Is there a decimal year output?
This page focuses on calendar breakdowns. Use the Age in Years calculator for decimal years.