About Age Calculator
Calculate your exact age from your date of birth — in years, months, and days — and see how many total days, weeks, or hours you have lived. Handy for forms, eligibility checks, and birthdays.
How to Use
- Enter your date of birth.
- Optionally set the 'age at' date (defaults to today).
- See your age in years, months, and days.
- Read the totals in days, weeks, and hours.
Why Use This Tool?
- Accurate — built on precise, well-tested mathematical formulas.
- Instant — all calculations happen client-side for zero latency.
- Private — no data is sent to any server; your information stays on your device.
- Free — no sign-up, no limits, no hidden costs.
Frequently Asked Questions
How is age calculated exactly?
Age is the difference between two dates broken into full years, then the remaining months, then the remaining days — accounting for different month lengths and leap years, not just dividing total days by 365.
Does it account for leap years?
Yes. Because it counts calendar years and months rather than a fixed 365-day year, leap days are handled correctly.
Can I calculate age on a future or past date?
Yes — set the 'age at' date to any date to find how old someone was, or will be, on that day.