Age Calculator
Enter your date of birth to calculate your exact age in years, months, and days. You can also see how long until your next birthday and other useful age details.
Your exact age
Every calculation runs in your browser — your dates are never uploaded or stored on our servers.
About this age calculator
This tool works out your exact age from your date of birth using real calendar arithmetic, so it accounts for different month lengths and leap years rather than approximating with "365 days a year". Enter your birth date, and optionally change the second date to calculate your age at any point in the past or future. Everything runs in your browser — your dates are never sent anywhere.
How to calculate your age
Enter your date of birth in the first field. The second field, "Age on date", fills in with today's date automatically, so most people can just press Calculate Age. The result shows your age in complete years, months, and days, along with your next birthday and your age expressed in weeks and days.
How exact age is calculated
Exact age is measured in whole calendar units, not decimals. The calculator counts the number of full years between the two dates, then the number of full months since your most recent birthday, then the leftover days. For example, someone born on 20 May 1990 is exactly 35 years, 0 months, 0 days old on 20 May 2025, and 34 years, 11 months, 29 days old the day before. Because months vary in length, the "days" figure is measured against the length of the relevant month rather than a fixed 30.
How leap years affect age calculations
Leap years add a 29th day to February every four years (with the usual century exceptions). This calculator uses each year's real length, so a birthday that has or hasn't passed is judged correctly regardless of leap days in between. If you were born on 29 February, your birthday only falls on that exact date in leap years; in other years this calculator treats 1 March as your birthday for the "next birthday" countdown, which keeps the logic consistent.
How to calculate age on a specific date
Change the "Age on date" field to any date you like. Set it to a past date to see how old you were at a particular event, or a future date to see how old you'll be. The calculator won't produce a negative age: if the birth date is later than the "age on" date, it shows a short message asking you to check the dates.
How long until my next birthday?
The result includes your next birthday and a calendar-aware countdown to it, measured in months and days as well as a total number of days. The countdown is relative to the "Age on date" field, so if you change that date, the countdown updates to match. If the selected date is your birthday, the calculator says so.
Practical examples
- Born 1 January 2000, calculated on 1 January 2025 → 25 years, 0 months, 0 days.
- Born 1 January 2000, calculated on 31 December 2024 → 24 years, 11 months, 30 days.
- Born 15 July 1995, calculated on 14 July 2025 → 29 years, 11 months, 29 days.
- Born 29 February 2000, calculated on 1 March 2025 → 25 years, 0 months, 0 days (1 March is treated as the birthday in non-leap years).
Frequently asked questions
How do I calculate my exact age?
Enter your date of birth and press Calculate Age. The second date defaults to today, so the result is your exact current age in years, months, and days.
Does this calculator include months and days?
Yes. It shows complete years, complete months since your last birthday, and the remaining days — for example "35 years, 0 months, 0 days". It also shows your age in total weeks and total days.
Can I calculate my age on a past date?
Yes. Change the "Age on date" field to any past date to see how old you were then.
Can I calculate age on a future date?
Yes. Set "Age on date" to a future date to see how old you'll be, and how long you have until then.
How are leap-year birthdays handled?
If you were born on 29 February, that exact date only exists in leap years. For the next-birthday countdown in other years, the calculator treats 1 March as your birthday, which keeps the arithmetic consistent. Your age total is always calculated with each year's real length.
How many days old am I?
The result includes "Total days", which is the exact number of calendar days between your birth date and the selected date, and "Total weeks", derived from that day count.
How long until my next birthday?
The result shows your next birthday's date and a countdown in months and days (plus a total number of days), measured from the "Age on date" field.
Is this age calculator free?
Yes — completely free, with no account and no limits.
Are my dates uploaded anywhere?
No. Every calculation happens locally in your browser. Your birth date and the dates you enter are never uploaded to ToolLora's servers or stored anywhere.