How to Calculate Your Age in Hijri Years (and Why It Is Higher)

Most people have never thought about their age in the Islamic calendar — until a form asks for a Hijri date of birth, or a friend points out that they are already a year “older” in Hijri years. This guide explains why your Hijri age is higher, how to calculate it exactly, and where it actually matters.

Why your Hijri age is higher

A Gregorian year has 365 or 366 days. A Hijri year has 354 or 355. Over a lifetime, the difference accumulates: about 11 days a year, which adds up to a full extra year roughly every 33 years.

Gregorian age	Days lived (approx.)	Hijri age
10	3,652	10 years, 3–4 months
18	6,574	18 years, 6–7 months
33	12,053	about 34
40	14,610	about 41
63	23,010	about 65

Notice the last row. The Prophet ﷺ is reported to have died at the age of 63 — counted in lunar years, as the companions reckoned time. In Gregorian terms that is about 61.

Step 1: find your Hijri birth date

Start by converting your Gregorian birth date to the Hijri calendar. You can do it by hand (see our guide on converting dates by hand) or with the converter.

Example: someone born on 15 May 1990. On the Umm al-Qura calendar that is 20 Shawwal 1410.

Two cautions:

• The method matters. The tabular calendar may give a date a day or two different from Umm al-Qura. For a modern birth date, Umm al-Qura is the better choice; for Saudi documents it is the required one.
• Evening births. The Islamic day begins at sunset. If you were born after sunset, some would count your Hijri birthday as the next day. Official documents normally use the civil date, so follow the date already on your papers.

Step 2: find today’s Hijri date

Look up today’s Hijri date on the home page. As of 15 October 2026, it is 4 Jumada al-Ula 1448.

Step 3: subtract, Hijri-style

Subtract the birth date from today’s date, borrowing months and days as you would with any calendar — but remembering that Hijri months have 29 or 30 days and a Hijri year has 12 months.

Example (born 20 Shawwal 1410, today 4 Jumada al-Ula 1448):

1. Years: 1448 − 1410 = 38. But Jumada al-Ula (month 5) comes before Shawwal (month 10), so this year’s Hijri birthday has not happened yet. Years = 37.
2. Months: from 20 Shawwal 1447 to 20 Rabi’ al-Thani 1448 is 6 months (Dhul-Qa’dah, Dhul-Hijjah, Muharram, Safar, Rabi’ al-Awwal, Rabi’ al-Thani). The next “monthiversary”, 20 Jumada al-Ula, has not arrived. Months = 6.
3. Days: from 20 Rabi’ al-Thani 1448 to 4 Jumada al-Ula 1448. Rabi’ al-Thani 1448 has 30 days, so that is 10 days to the end of the month plus 4 = 14 days.

Hijri age: 37 years, 6 months, 14 days.

For comparison, the same person’s Gregorian age on 15 October 2026 is 36 years, 5 months. They are already in their 38th Hijri year while still in their 37th Gregorian year.

Faster: count days and divide

If you only need a decimal age, there is a shortcut:

1. Count the days you have lived (a date-difference tool will do this).
2. Divide by 354.367, the average Hijri year.

For our example, 15 May 1990 to 15 October 2026 is 13,302 days. 13,302 ÷ 354.367 = 37.54 Hijri years — consistent with 37 years and about 6½ months.

The Hijri age calculator does both calculations for you and shows your Hijri birth date.

Your Hijri birthday moves

Because your Hijri birthday is fixed in the Hijri calendar, it falls on a different Gregorian date every year — about 11 days earlier each time. Our example person’s Hijri birthday, 20 Shawwal, falls on:

• 28 March 2027 (20 Shawwal 1448)
• 16 March 2028 (20 Shawwal 1449)

Some families like to mark both. It is also a gentle reminder that the Islamic calendar measures life in moons.

Where Hijri age actually matters

Hijri age is mostly a curiosity, but there are situations where it is used:

Islamic law (fiqh). Classical rulings that mention ages — for example, the age at which a child is considered to have reached maturity if no physical signs have appeared, which many schools set at 15 — are expressed in lunar years. In practice, 15 lunar years is about 14 years and 7 months in Gregorian terms. Scholars discuss these matters in detail; if a question of maturity, guardianship or inheritance arises, ask a qualified scholar rather than relying on a calculator.

Zakat. Zakat on savings becomes due after wealth has been held for one full lunar year (hawl). This is about the anniversary of your zakat date, not your age, but it uses the same calendar arithmetic.

Saudi documents. Older Saudi identity documents, and many forms, record the date of birth in the Hijri calendar. If your passport has a Gregorian date, the Hijri equivalent should be calculated with Umm al-Qura. Errors of one day are common when people use a tabular converter — if your documents disagree, the date on your official ID is the one that counts.

Personal reflection. Many Muslims simply find it meaningful to know their age in the calendar of their worship — especially around milestones such as 40, which the Quran mentions as the age of full maturity (46:15).

Hijri age at common milestones

It can be surprising how early the Hijri count pulls ahead. This table shows the Gregorian age at which you reach some Hijri milestones:

Hijri age reached	Gregorian age at that moment
7 Hijri years	about 6 years, 9 months
10 Hijri years	about 9 years, 8 months
15 Hijri years	about 14 years, 7 months
18 Hijri years	about 17 years, 6 months
40 Hijri years	about 38 years, 10 months
60 Hijri years	about 58 years, 3 months
63 Hijri years	about 61 years, 1 month

The ages 7 and 10 appear in the well-known hadith about teaching children to pray, and many parents simply use Gregorian birthdays for these. Scholars generally regard the guidance as being about stages of development rather than exact calendar dates, so there is no need to calculate them to the day.

A worked example for a child

A child born on 1 January 2020 is, on the Umm al-Qura calendar, born on 6 Jumada al-Ula 1441. On 15 October 2026 (4 Jumada al-Ula 1448), the child is:

• 6 years, 9 months old in Gregorian terms, and
• 6 years, 11 months and 28 days old in Hijri terms — two days short of their seventh Hijri birthday on 6 Jumada al-Ula 1448 (17 October 2026).

That gap — almost three months at age seven — grows steadily. By the time the child is 33, it will be a full year.

Common mistakes

• Using 365-day years. Dividing days lived by 365 gives your Gregorian age, not your Hijri age.
• Assuming all months have 30 days. About half of Hijri months have 29 days. Borrowing a “30-day month” when the month only had 29 makes the day count wrong by one.
• Mixing methods. Convert both the birth date and today’s date with the same calendar method.
• Forgetting the month order. Check whether this year’s Hijri birthday has passed by comparing month numbers: Shawwal is 10, Jumada al-Ula is 5, and so on.

Quick reference

• Hijri age ≈ Gregorian age × 1.0307
• You gain about one Hijri year every 33 Gregorian years
• Your Hijri birthday comes about 11 days earlier every year

For an exact answer to the day, use the Hijri age calculator — it shows your age in Hijri years, months and days alongside your Gregorian age.