Age Calculator
Exact age in years, months and days, plus your next birthday
How to Use
- 1Pick your date of birth in the first field.
- 2Leave the second field on today, or set any past or future date.
- 3Read your exact age, and the tiles add months, weeks, days and hours.
- 4The note tells you which weekday you were born on and when you next turn a year older.
Try a date:
How Age Is Counted
- YearsCompleted birthdays, not rounded up
- MonthsWhole months since your last birthday
- DaysDays since that month mark
- Leap yearsHandled exactly, no 365-day shortcut
Your Milestones
Updates as you change the date of birth.
- MilestonesEnter a date of birth
Everything about the Age Calculator
Why "how old am I" is a calendar question, not a division problem.
This age calculator gives your exact age in years, months and days from your date of birth, and because it walks the calendar month by month instead of dividing a day count by 365.25, it never drifts by a day around leap years or long months.
Enter a birth date, leave the second field on today, and you get the answer instantly. Change the second field to work out how old someone was on a particular date, or how old they will be at a future event.
The borrowing rule: from 31 January to 1 March is 1 month and 1 day, not 29 days. When the day number comes out negative, one month is borrowed, and the size of that month is the month before the end date. That single detail is what most quick age formulas get wrong.
Worked example
Born 15 June 1990, measured on 6 August 2026:
| Step | Working | Result |
|---|---|---|
| Years | 2026 − 1990 | 36 |
| Months | August (8) − June (6) | 2 |
| Days | 6 − 15 → borrow 31 days from July | 22 |
| Adjust | Months drop from 2 to 1 after borrowing | 36 y 1 m 22 d |
How your age is counted around the world
- 1Western reckoning (used here)
You are 0 at birth and gain a year on each birthday. This is the legal standard in most countries and the answer this calculator gives.
- 2East Asian age reckoning
Traditionally a baby is 1 at birth and everyone gains a year at new year, so a person can be up to two years "older" than their western age. South Korea moved to western age in law in June 2023.
- 3Insurance "nearest birthday"
Some life insurers round to the nearest birthday, so seven months after turning 40 you are already priced as 41. Always check which definition a form is asking for.
Leap-day birthdays
People born on 29 February have a real birthday only every four years. For counting purposes this calculator treats 28 February as the anniversary in common years, which is what most registries and driving-licence rules use. In a leap year the real 29 February date is used.
What the extra tiles are for
Age in days is what visa forms, medical dosage charts and paediatric growth charts ask for. Age in months is standard for babies and toddlers. Age in hours is mostly for fun, but the 10,000-day milestone (about 27 years 4 months) has quietly become a birthday people celebrate.
Frequently Asked Questions
How do I calculate my exact age?
Enter your date of birth and leave the second field on today's date. Your age appears immediately as years, months and days, and the tiles below convert it to total months, weeks, days and hours.
How many days old am I?
The "In days" tile gives the exact count, including every leap day you have lived through. As a rough guide, 10,000 days is about 27 years and 4 months, and 20,000 days is about 54 years and 9 months.
Can I work out how old I was on a past date?
Yes. Change the "Age at the date of" field to any past date, which is useful for visa applications, school-entry cut-offs and legal paperwork that asks for your age on a specific day. A future date works too, so you can check how old you will be at a wedding or exam date.
How does the calculator handle a 29 February birthday?
In a leap year the birthday falls on 29 February as normal. In a common year the anniversary is treated as 28 February, which is the convention most official registries use, so your age still increases every year rather than every four.
Why does my age show fewer days than 365 × my years?
Because a year is 365.2425 days, not 365. Multiplying your age by 365 loses roughly one day for every four years lived. This calculator counts real calendar days instead, so the figure matches what a registrar would compute.
When is my next birthday and what day will it fall on?
The line under your age gives the date of your next birthday, the age you will turn and the weekday it lands on. The "Next birthday" tile counts down the days, and the Milestones panel shows when you reach 18, 21, 40, 50, 60, 65 and 10,000 days.
Is the age calculator free and is my birth date stored?
It is 100% free with no sign-up, and every calculation runs inside your browser, so your date of birth is never sent to a server or saved anywhere.