Easter Date Calculator
This Easter date calculator — also searched as an Easter Sunday date calculator — works out the exact date of Easter Sunday for any year from 326 to 9999 — Gregorian (Western) or Julian (Orthodox), your choice. Step the year or type a new one and the date above updates instantly, no submit button and nothing sent anywhere: the whole calculation runs in your browser.
How This Easter Date Calculator Works
Western churches fix Easter Sunday using the Anonymous Gregorian algorithm — the closed-form version of Computus worked out by Meeus, Jones, and Butcher. It finds the Paschal Full Moon (the first ecclesiastical full moon on or after March 21) for the year you enter, then steps forward to the following Sunday. No lookup table is involved: it's a short sequence of modulo and division steps against the year's position in the 19-year lunar cycle and the Gregorian calendar's century-based corrections, so it resolves instantly for any year in range. This Easter date calculation formula — also called the Easter date calculation algorithm — is exactly what powers the instant result above.
Easter Sunday = April 5
Why Easter's Date Changes Every Year
Easter isn't pinned to a fixed date the way Christmas is. It's defined as the first Sunday after the Paschal Full Moon — a lunar event that lands on a different calendar date most years. That rule, inherited from the timing of the Jewish Passover, is why Easter Sunday drifts across a roughly five-week window (March 22 to April 25) instead of sitting still on the calendar.
Gregorian (Western) vs. Orthodox Easter
The Julian/Orthodox toggle switches which calendar computes the Paschal Full Moon. Orthodox churches never adopted the 1582 Gregorian calendar reform, so they still calculate it on the older Julian calendar (the Meeus Julian algorithm). This calculator then converts that result to the Gregorian civil date — the date on the calendar everyone actually uses — the same way every real Orthodox Easter reference does, rather than showing an Old-Style Julian date that wouldn't match anyone's calendar. The Julian calendar currently runs 13 days behind the Gregorian one, which is why Orthodox Easter usually falls one to five weeks after Western Easter, and occasionally on the same Sunday. If you're asking when is Orthodox Easter this year, or looking for how Orthodox Easter date calculation (sometimes called Eastern Orthodox Easter date calculation) actually works, this toggle is that calculation, done instantly.
Frequently asked questions
Why does Easter change dates every year?
Easter follows a lunar-solar rule, not a fixed date on the solar calendar. It falls on the first Sunday after the Paschal Full Moon — the first ecclesiastical full moon on or after March 21. Because that full moon lands on a different date most years, Easter Sunday can fall anywhere between March 22 and April 25 on the Gregorian calendar.
How is the date of Easter calculated?
Western churches use the Anonymous Gregorian algorithm (often called Computus, in the form worked out by Meeus, Jones, and Butcher). It combines the year's position in the 19-year lunar cycle with century-based corrections to the Gregorian calendar to find the Paschal Full Moon, then steps forward to the following Sunday. This calculator runs that exact algorithm the moment you enter a year.
What is the formula for the date of Easter?
The Meeus/Jones/Butcher formula derives the year's "golden number" (its position in the 19-year Metonic lunar cycle) and century-based leap-year corrections, combines them through a short sequence of modulo and division steps, and resolves the result to a month and day. It's a closed-form calculation — no lookup tables — which is why it can be computed instantly for any year from 326 to 9999.
How is the date of Orthodox Easter calculated?
Orthodox churches calculate the Paschal Full Moon using the older Julian calendar (the Meeus Julian algorithm) rather than the Gregorian one. That Julian-calendar date is then converted to the Gregorian civil date everyone's calendar actually uses — currently a 13-day shift — which is why Orthodox Easter usually falls one to five weeks after Western Easter, and occasionally on the same day.
Why does Easter's date change every year but not Christmas?
Christmas was fixed to December 25 on the solar calendar independent of any lunar cycle. Easter's date comes from a much older lunar-solar rule, tied to the timing of the Jewish Passover, so it moves with the moon's phase from year to year instead of sitting on a fixed calendar date.
