# Easter Date Calculator (Western and Orthodox)

URL: https://speedycalculator.com/calculators/other/easter/
Last updated: 2026-10-30

> The Easter date calculator finds Easter Sunday for any year from 1583 onwards with the Gregorian computus, the Orthodox (Julian) Easter date, the gap between them and the movable feasts that hang on Easter – from Ash Wednesday to Pentecost and Corpus Christi.

## Inputs

- Year

## Results

- Western Easter Sunday
- Orthodox Easter Sunday (Gregorian date)
- Orthodox Easter is later by
- Ash Wednesday
- Palm Sunday
- Good Friday
- Easter Monday
- Ascension Day
- Pentecost (Whitsunday)
- Corpus Christi
- Orthodox Good Friday
- Golden number (year in the 19-year lunar cycle)
- Days from today to Western Easter

## Formula

```
Western: a = y mod 19, b = ⌊y/100⌋, c = y mod 100, d = ⌊b/4⌋, e = b mod 4, f = ⌊(b+8)/25⌋, g = ⌊(b−f+1)/3⌋, h = (19a+b−d−g+15) mod 30, i = ⌊c/4⌋, k = c mod 4, l = (32+2e+2i−h−k) mod 7, m = ⌊(a+11h+22l)/451⌋, month = ⌊(h+l−7m+114)/31⌋, day = ((h+l−7m+114) mod 31) + 1 · Orthodox (Meeus): d = (19(y mod 19)+15) mod 30, e = (2(y mod 4)+4(y mod 7)−d+34) mod 7, Julian date = day ((d+e+114) mod 31)+1 of month ⌊(d+e+114)/31⌋, plus ⌊y/100⌋ − ⌊y/400⌋ − 2 days
```

## Explanation

Easter is a movable feast. The rule set at the Council of Nicaea and refined over the following centuries says Easter is the first Sunday after the ecclesiastical full moon that falls on or after 21 March. The "full moon" here is not the astronomical one but a value from church tables (the computus), which follow the 19-year Metonic cycle of the Moon. As a result Western Easter always falls between 22 March and 25 April.

Orthodox churches use the same principle but keep the Julian calendar and the older lunar tables. Their Easter therefore lands between 4 April and 8 May in today's civil calendar. In about a third of years both churches celebrate on the same Sunday (as in 2025 and 2028); otherwise Orthodox Easter is one, four or five weeks later.

The calculator evaluates both algorithms for the year you enter and builds the church year around them: Ash Wednesday 46 days before Easter, Palm Sunday, Good Friday, Easter Monday, Ascension Day (39 days after), Pentecost (49 days after) and Corpus Christi (60 days after).

### How to use the Easter Date Calculator

- **Year**

Results update as you type, every field has its own unit menu, and everything is calculated in your browser.

### How it works

Enter a year. The Western date comes from the anonymous Gregorian algorithm (Meeus/Jones/Butcher); the Orthodox date comes from Meeus' Julian algorithm converted to the Gregorian calendar by adding the century difference (13 days from 1900 to 2099).

### Worked example

For 2027: a = 13, b = 20, c = 27, d = 5, e = 0, f = 1, g = 6, h = (247 + 20 − 5 − 6 + 15) mod 30 = 1, i = 6, k = 3, l = (32 + 0 + 12 − 1 − 3) mod 7 = 5, m = 0. Then h + l − 7m + 114 = 120, so month = ⌊120/31⌋ = 3 (March) and day = (120 mod 31) + 1 = 28: **Easter Sunday is 28 March 2027**. The Orthodox rule gives d = 22, e = 6 and Julian 19 April, which is 2 May 2027 in the Gregorian calendar.

### Easter dates 2025–2035

YearWestern EasterOrthodox EasterGap2025April 20April 20Same day2026April 5April 121 week2027March 28May 25 weeks2028April 16April 16Same day2029April 1April 81 week2030April 21April 281 week2031April 13April 13Same day2032March 28May 25 weeks2033April 17April 241 week2034April 9April 9Same day2035March 25April 295 weeks

### What each result means

- **Western Easter Sunday** = date([Year], floor(([h] + [l] - 7×[m] + 114)÷31), mod([h] + [l] - 7×[m] + 114, 31) + 1)
- **Orthodox Easter is later by** = [Orthodox Easter Sunday (Gregorian date)] - [Western Easter Sunday]
- **Ash Wednesday** = [Western Easter Sunday] - 46
- **Palm Sunday** = [Western Easter Sunday] - 7
- **Good Friday** = [Western Easter Sunday] - 2
- **Easter Monday** = [Western Easter Sunday] + 1
- **Ascension Day** = [Western Easter Sunday] + 39
- **Pentecost (Whitsunday)** = [Western Easter Sunday] + 49
- **Corpus Christi** = [Western Easter Sunday] + 60
- **Orthodox Good Friday** = [Orthodox Easter Sunday (Gregorian date)] - 2
- **Golden number (year in the 19-year lunar cycle)** = [a] + 1
- **Days from today to Western Easter** = [Western Easter Sunday] - today()

## Worked example

Inputs — Year: 2,027.

Results — **Western Easter Sunday = Sun, March 28, 2027**; Orthodox Easter Sunday (Gregorian date) = Sun, May 2, 2027; Orthodox Easter is later by = 35 days; Ash Wednesday = Wed, February 10, 2027; Palm Sunday = Sun, March 21, 2027; Good Friday = Fri, March 26, 2027; Easter Monday = Mon, March 29, 2027; Ascension Day = Thu, May 6, 2027; Pentecost (Whitsunday) = Sun, May 16, 2027; Corpus Christi = Thu, May 27, 2027; Orthodox Good Friday = Fri, April 30, 2027; Golden number (year in the 19-year lunar cycle) = 14; Days from today to Western Easter = 148 days.

## Key terms

- **Computus**: The calculation of the date of Easter from calendar and lunar tables.
- **Paschal full moon**: The ecclesiastical full moon on or after 21 March; Easter is the following Sunday.
- **Metonic cycle**: 19 years ≈ 235 lunar months, after which moon phases repeat on the same dates.
- **Movable feast**: A church holiday whose date depends on Easter, such as Pentecost.

## FAQ

**When is Easter 2027?**
Western Easter is on Sunday 28 March 2027 and Orthodox Easter on Sunday 2 May 2027 – five weeks apart.

**What is the earliest and latest possible Easter?**
Western Easter falls between 22 March and 25 April. The next 22 March Easter is in 2285; the last 25 April Easter was in 1943 and the next is in 2038.

**Why do Western and Orthodox Easter differ?**
The Orthodox churches compute Easter in the Julian calendar with the older lunar tables, which now run 13 days behind for the calendar and several days behind for the Moon.

**When do both churches celebrate Easter together?**
When both rules give the same Sunday – for example in 2025 (20 April), 2028 (16 April), 2031 (13 April) and 2034 (9 April).

**Is Easter the Sunday after the first full moon of spring?**
Approximately. The church uses a tabulated "ecclesiastical" full moon and fixes the equinox at 21 March, so in some years the date differs from the astronomical rule.

**How is Ash Wednesday calculated?**
46 days before Easter Sunday – 40 days of Lent plus the six Sundays, which are not counted as fast days.

**What is the golden number?**
The position of the year in the 19-year Metonic cycle (1 to 19); it determines the date of the ecclesiastical full moon.


## Sources

- [U.S. Naval Observatory – The date of Easter](https://aa.usno.navy.mil/faq/easter)
- [Date of Easter – Wikipedia](https://en.wikipedia.org/wiki/Date_of_Easter)
