Age Calculator — Calculate Age by Date of Birth in Years, Months, Days | ToolCircuit
Calculate your age online by date of birth in years, months, and days. Add a target date, see total months/weeks/days, day of week born, and next birthday countdown.
No uploads. Everything runs locally in your browser.
Calculate age in years, months, and days by date of birth, or set a future/past target date to see age on a specific day. Totals for months, weeks, and days are included with a next-birthday countdown.
Runs fully client-side for speed and privacy. Works with leap years and handles invalid future birth dates gracefully.
Enter a date of birth and tap Calculate to see the age breakdown.
Benefits & use cases
- Quickly answer “How old am I today?” with clear years/months/days.
- Check age on a specific date for travel forms, visa, school, or eligibility rules.
- See next-birthday countdown for planning reminders and celebrations.
- Keep totals (months/weeks/days) for milestone tracking and fitness or finance goals.
How the age calculation works
The calculator compares your birth date to the target date, borrowing days from the previous month when needed so months and days stay accurate. Leap years are handled explicitly, and Feb 29 birthdays roll to Feb 28 in non-leap years for the next-birthday countdown. All math runs in your browser for privacy.
How to use
- Enter your date of birth and optionally a target date (defaults to today).
- Click Calculate to see age in years, months, and days plus totals and next birthday.
- Copy the result or clear to start over; use Today or sample presets for quick checks.
Features
- Accurate age in years, months, days with leap-year-safe logic
- Optional target date to see age on a specific day
- Totals: months, weeks, days + day of week born
- Next birthday countdown and date
- Copy result, clear, today shortcut, and sample preset
- Runs client-side for privacy
FAQ
How is the age calculated?
We compare your birth date to the target date, adjusting months and days correctly (including leap years) to avoid rounding errors.
Can I check age on a past or future date?
Yes. Set a target date to see age on that day. The target must be on or after the birth date.
Do you support leap-year birthdays?
Yes. Feb 29 birthdays roll to Feb 28 in non-leap years for next-birthday countdowns.
Is my date of birth stored?
No. Everything runs in your browser; nothing is uploaded.
Can I copy the result?
Yes. Use Copy result to place the age breakdown on your clipboard.