What this calculator gives you
This tool calculates your exact age in years, months and days from your date of birth, entered in either the Gregorian or the Hijri calendar. Alongside your age it shows:
- your birth date on both calendars and the weekday you were born;
- your age in Hijri years next to your Gregorian age;
- your next birthday on both calendars and the days remaining;
- your age in months, weeks, days, hours, minutes and seconds;
- upcoming milestones such as turning 18, 30 or 40, or your 10,000th day;
- your age on any past or future date you choose.
How exact age is determined
Exact age is the number of complete years since birth, then complete months since the last birthday, then the remaining days. The calculator finds the latest monthly anniversary of your birth date that does not pass the target date, and counts days from there.
Two cases need an explicit rule:
- Born on 29 February: in common years your birthday is counted on 28 February.
- Born on the last day of a long month (e.g. 31 January): the monthly anniversary in a shorter month falls on that month’s last day.
Worked example
Someone born on Monday 15 March 1999, measured on 1 January 2026:
| Unit | Result |
|---|---|
| Age | 26 years, 9 months and 17 days |
| Months | 321 |
| Weeks | 1,398 weeks and 3 days |
| Days | 9,789 |
| Hijri age | 27 years, 7 months and 15 days |
Calculating your age by hand
Subtract the birth date from the target date, working from days to months to years and borrowing when needed:
- Days: if the target day is smaller than the birth day, add the length of the month before the target date and take one month away.
- Months: if the month is now smaller than the birth month, add 12 and take one year away.
- Years: subtract the birth year.
For the example: 1 is smaller than 15, so borrow December (31 days): 1 + 31 − 15 = 17 days. January minus one month is 0, smaller than March, so borrow a year: 12 − 3 = 9 months. Finally 2025 − 1999 = 26 years.
Near month ends the manual method can differ by a day, because borrowing depends only on the previous month’s length. The calculator applies the anniversary rule above consistently.
Gregorian age vs Hijri age
A Hijri year has 12 lunar months of 29 or 30 days, 354 or 355 days in total, about 11 days shorter than a Gregorian year. That is why your Hijri age runs ahead of your Gregorian age, by roughly one year for every 33. See the Hijri Age Calculator for details.
How the birthday countdown works
The calculator finds the nearest anniversary of your birth date that falls today or later, then counts the days and names the weekday. It does this on both calendars. Your Hijri birthday moves about 11 days earlier every Gregorian year. In the example above, on 1 January 2026 the next birthday is Sunday 15 March 2026, 73 days away; the Hijri birthday (26 Dhu al-Qadah 1447 AH) falls on 13 May 2026.
Limitations
- “Today” uses Riyadh time by default; switch to your device’s time zone in Settings.
- Hours, minutes and seconds count from midnight on your birth date unless you enter a time of birth.
- Hijri conversion is exact within the Umm al-Qura range (1300–1600 AH); outside it the arithmetic Hijri calendar is used and flagged as approximate.
- For official purposes, rely on the date in your documents. This is an independent calculation tool.
Privacy
Your birth date is processed in your browser only. It is never sent to a server or recorded in analytics. If you tick “Remember my birth date on this device”, it is stored in your browser only and removed when you untick it or press Clear. See the Privacy Policy.
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