Age Calculator
Calculate exact age from a birth date, the difference between two dates, or the days until the next birthday. Everything runs in your browser, no signup.
The calculator works in the secular (Gregorian) calendar only, not the Hebrew calendar. It is not medical, legal, or astrological advice, and does not address age for military service, a license, retirement, or any other eligibility. Everything runs in your browser.
A free age calculator to calculate age from a date of birth, find the age between two dates, and count the days until the next birthday. If you have ever asked "how old am I?" and wanted the answer as an exact age in years, months, and days rather than a rounded number, this is the tool. Three separate modes: "Age now" (your age by birth date from a date of birth to today, or to a target date you choose), "Date difference" (how many days, weeks, months, and years between two dates you pick), and "Until next birthday" (the date of the upcoming birthday, days remaining, the weekday, and the age reached on that birthday). The calculator works in the secular (Gregorian) calendar only, not the Hebrew calendar. It does not rely on astrology, does not give a personality reading, does not address age for military service, a driving license, retirement, or any legal eligibility, and is not medical advice. Everything happens in your browser: the birth date, target dates, and reference date never leave the device, are not stored, and are not sent to a server. Refreshing the page clears the input. No signup and no tracking of the calculation content. Last updated: May 2026.
How to use this tool
- 01Choose a calculation type"Age now" calculates age from a birth date to today (or to a target date you choose). "Date difference" measures how much time passed between two different dates. "Until next birthday" counts down to the upcoming birthday, including the weekday and the age you will reach.
- 02Enter a datePick a date with the browser date picker. The allowed range is 1900 to 2100. Invalid dates (for example February 31) are rejected with a clear message. A future birth date is not allowed in "Age now" mode.
- 03Get an instant resultThe result updates as you type. The tool shows the exact age in years/months/days, total months, total weeks, total days, the weekday of the birth date, and in "Until next birthday" mode also the upcoming date and the age you will reach.
- 04Copy a summaryThe "Copy summary" button copies a plain-text summary with all the details. Handy for sending to a partner or family member, or for keeping a personal record.
When is this useful?
- Checking an exact age for a formMany forms ask for "exact age" or "age on a specific day". Enter a birth date and the target date, and get years/months/days ready to copy.
- A child's age for schoolParents who need to know exactly how old a child is on the first day of school. Enter the birth date and the start date, and get the exact age.
- Counting down to a birthdayThe "Until next birthday" mode shows exactly how many days are left, the weekday, and the exact date. If the birthday is today, it clearly shows "Today!".
- The gap between two events"Date difference" works for any pair of dates: how long you have been together, how many days since a trip, how long until a future event. Both past and future dates are allowed.
- A family member's age on a given dayWant to know how old a grandparent was on the day you were born? Enter their birth date and your birth date as the "target date". You get their exact age on that day.
Examples
- Age from March 15, 1990, to today"Age now" mode with birth date 1990-03-15 (no target date). You get the exact age in years/months/days, total days since birth, total weeks, total months, and the weekday of the birth date.
- Difference between January 1, 2020 and May 27, 2026"Date difference" mode with start date 2020-01-01 and end date 2026-05-27. You get 6 years, 4 months, 26 days (about 2,338 days, ~334 weeks, ~76 months), noting the second date is after the first.
- Next birthday for someone born March 15, 1990"Until next birthday" mode with birth date 1990-03-15, when today is May 27, 2026. The upcoming birthday is March 15, 2027 (a Monday). About 292 days remain. The age on that birthday will be 37.
- When today is the birthday"Until next birthday" mode with a birth date matching today: it shows "Today!" instead of days remaining, and the weeks and days counters show 0 so nothing is misleading.
Tips for a better result
- You can enter a future target dateIn "Age now" mode you can check how old you will be on a specific future date: a wedding, a family event, a trip. Just enter the future date in the "target date" field.
- If the birthday is February 29The tool uses February 29 in leap years. In non-leap years, "Until next birthday" mode shows March 1 as the upcoming birthday. This is a common convention; feel free to celebrate on whichever day suits you.
- The tool does not use the Hebrew calendarIf you want the age by the Hebrew calendar (the Hebrew date of birth), this tool does not provide that calculation. It works strictly by the secular (Gregorian) calendar. For the Hebrew calendar, use a suitable Hebrew calendar.
- Everything runs in your browserThe birth date and target dates never leave the device, are not stored, and are not sent to a server. You can use the tool in incognito mode or with no internet connection.
How to calculate age from a date of birth
To calculate age from a date of birth, the tool compares the birth date to the target date using date arithmetic: years = target year minus birth year, months = target month minus birth month, days = target day minus birth day. When the days are negative (for example the target day is the 5th and the birth day is the 28th), the tool borrows days from the previous month of the target date and subtracts one month. When the months are negative, it borrows from the previous year. This gives an age in a form people understand ("36 years, 2 months, 12 days") rather than a rough approximation ("36.21 years"). Total days are computed as Math.floor of the millisecond difference divided by 86400000, total weeks are Math.floor of total days divided by 7, and total months are an approximation of years times 12 plus months.
How leap years and February 29 are handled
In leap years (such as 2024 and 2028) the tool uses February 29. In non-leap years, "Until next birthday" mode shows March 1 as the upcoming birthday, a common convention. In "Age now" mode the math runs normally: when the target is February 28 in a non-leap year, the result is one day fewer than a full year. Leap-year rules follow the standard test: a year divisible by 4, except centuries that are not divisible by 400 (so 2000 is a leap year, 1900 and 2100 are not).
Finding the age between two dates
Beyond a single date of birth, the "Date difference" mode finds the age or span between two dates: pick a start date and an end date and the tool reports the result in years, months, and days, plus total months, total weeks, and total days. This is the same calculation many people want when they search for the age difference between two people, the time elapsed between two events, or simply how many days are between two dates. Both dates can be in the past or the future, and the order does not matter: the tool measures the gap either way and notes which date comes later.
How many days until your next birthday
To find how many days until your next birthday, switch to "Until next birthday" mode and enter your date of birth. The tool reports the exact date of the upcoming birthday, the number of days remaining, the weekday it falls on (for example Monday), and the age you will turn on that day. The countdown is measured against your local calendar date, so it always reflects today on your own device. When the birthday is today, the tool shows "Today!" and sets the days and weeks counters to 0 instead of rolling forward a full year.
Time zones
The tool uses your device time zone. All calculations are done on dates only, not on clock times. So if you were born at night in one time zone but the device is in another, the date is still computed by the device local clock. In most cases this is correct and sufficient. If you need precision down to the minute (for example an insurance policy with an age condition exact to the minute), consult the relevant party rather than relying on this tool.
Privacy
Everything happens in your browser. The birth date, target dates, and all input values are not stored, not uploaded, and not sent to analytics. Refreshing the page clears everything. No signup, no account, and no tracking of the calculation content. Nothing you enter is uploaded.
Frequently asked questions
What is an age calculator?
A tool that calculates exact age from a birth date, the difference between two dates, or the days left until the next birthday. It shows years, months, days, total months, total weeks, and total days. The calculation runs in your browser, with no signup.
How do I calculate age from a date of birth?
Choose "Age now" mode and enter the date of birth. By default the tool calculates the age from that date to today on your local calendar, giving the exact age in years, months, and days, plus total months, total weeks, and total days. To find the age on a specific day instead, add a target date and the tool calculates the age as of that date.
Can I find the age between two dates?
Yes. Switch to "Date difference" mode, enter a start date and an end date, and the tool reports the span between them in years, months, and days, plus total months, weeks, and days. Both dates can be in the past or the future, and the order does not matter.
How many days until my next birthday?
Use "Until next birthday" mode and enter your date of birth. The tool shows the date of the upcoming birthday, the number of days remaining, the weekday it falls on, and the age you will turn. The countdown is measured against the current date on your own device.
Does it handle leap-year birthdays (February 29)?
Yes. In leap years (such as 2024 and 2028) the tool uses February 29. In non-leap years, "Until next birthday" mode shows March 1 as the upcoming birthday, a common convention. In "Age now" mode the date math runs normally, so a February 28 target in a non-leap year comes out one day short of a full year.
Does the tool use the Hebrew calendar?
No. The calculator works in the secular (Gregorian) calendar only. If you want the age or the birthday date by the Hebrew calendar, use a Hebrew calendar. The tool does not convert dates between calendars.
How are people born on February 29 handled?
In leap years (such as 2024 and 2028) the tool uses February 29. In non-leap years, "Until next birthday" mode shows March 1 as the upcoming birthday, a common convention. In "Age now" mode the math runs normally: when the target is February 28 in a non-leap year, the result is one day fewer.
What happens if the birthday is today?
In "Until next birthday" mode, if today is the birthday, the tool shows "Today!" instead of a future date, and the days counter shows 0 (not 365). This avoids the false impression that you have to wait a whole year for the next birthday.
Does the tool provide info on retirement age, military service, or a driving license?
No. The tool is a purely technical calculation of age in years/months/days. It does not determine any legal eligibility. Retirement age, military service, a driving license, and any other eligibility are set by law and can change. For accurate information, consult the relevant authorities.
Does the tool show astrology, a horoscope, or a personality reading?
No. This is a purely technical age calculator. There is no astrology, no zodiac, no horoscope, and no personality or spiritual reading. The tool shows date calculations only.
Is the data I enter stored?
No. The whole calculation happens in the browser only. The birth date, target dates, and all input values are not stored, not sent to a server, and not passed to analytics. Refreshing the page clears everything.
What year range is allowed?
The allowed range is 1900 to 2100. Dates outside the range are blocked with a clear error message. In "Age now" mode, a future birth date is also blocked.
Can I use a past or future reference date?
Yes. In "Age now" mode you can set a target date in the past or the future to see the age on that day. In "Date difference" mode both dates can be past or future, in any order.
Is the tool free?
Yes. The tool is free, with no signup and no usage limit.
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