The Age in Hijri Years calculator converts your Gregorian (Western) date of birth into the Islamic lunar calendar and tells you how old you are in Hijri (AH) years. Because the Islamic year is shorter than the Gregorian one, your Hijri age is always a little higher than your usual age — a difference many people find surprising and meaningful for religious milestones and family records.
How it works
The Hijri year is a lunar year of 12 months totalling about 354 days, roughly 11 days shorter than the 365.25-day Gregorian year. The tool converts your Gregorian birth date and today’s date into the tabular (arithmetical civil) Islamic calendar, which is fully deterministic, then computes the difference in Hijri years. Because more short lunar years fit into the same span of time, your Hijri age exceeds your Gregorian age, and the gap grows by roughly one year every 33 years of life.
Two Islamic calendars: tabular vs. observational
The Islamic calendar used for civil and administrative purposes in many countries is the tabular (arithmetical) calendar, which follows a fixed 30-year cycle of 19 ordinary years (354 days) and 11 leap years (355 days). This is fully deterministic — any date can be computed without observation — and is what this tool uses.
A separate tradition uses the observational calendar, which begins each new month when the crescent moon is actually sighted. This calendar is used for determining the start of Ramadan, Eid, and other religious occasions. The two can differ by a day or two, which is why the calculated Hijri dates here may occasionally diverge from a religious announcement in your locality.
Example
Someone born on 1 January 1990 has lived about 36 Gregorian years by 2026. In Hijri years that span is approximately:
36 × (365.25 ÷ 354.37) ≈ 37 Hijri years.
| Calendar | Year length | Age (approx) |
|---|---|---|
| Gregorian | 365.25 days | 36 years |
| Hijri (lunar) | 354.37 days | ~37 years |
When this is useful
- Religious milestones. In some Islamic traditions, certain religious obligations and rites of passage are tied to Hijri age, not Gregorian age.
- Historical dates. Classical Islamic texts and historical records use the AH dating system. Knowing your Hijri birth year can help contextualise dates in those sources.
- Family records and genealogy. Many official documents from the early twentieth century and before in Muslim-majority countries recorded dates in the Hijri calendar.
- Curiosity. The divergence between the two systems means your Hijri birthday falls on a different Gregorian date every year, cycling through the entire Gregorian calendar over about 33 years.
Everything runs in your browser — your date of birth is never uploaded or stored.