Prayer Time Calculation Methods: Which One Should You Use?
MWL, ISNA, Umm al-Qura, Egypt, Karachi, Diyanet and more: the angles each uses, who follows which, why Fajr differs by 20-40 minutes, how to choose.
Open two prayer apps side by side and you may see the same Dhuhr, the same Maghrib, and a Fajr that differs by half an hour. Neither app is broken. They are using different calculation methods, and a method is just a set of answers to one question: how far below the horizon must the sun be for dawn to have broken and for twilight to have ended?
This article lists the common methods, who uses them, why they disagree, and how to pick one without turning it into a debate.
What a method decides
As explained in how prayer times are calculated, sunrise, Dhuhr, Asr and Maghrib follow directly from the sun's position and are the same under every method. The method sets:
- The Fajr angle: how far below the horizon the sun is at true dawn. Typical values 15° to 20°.
- The Isha angle: how far below the horizon the sun is when the red twilight has gone. Typical values 14° to 18°, or a fixed number of minutes after Maghrib.
- Sometimes a Maghrib angle (Shia methods add a few degrees after sunset), and precaution minutes added by national authorities.
The Asr shadow rule (standard or Hanafi) is a separate setting, not part of the method; see Asr time: Hanafi and standard.
The methods and their angles
| Method | Fajr / Isha |
|---|---|
| Muslim World League | Fajr 18°, Isha 17° |
| ISNA (North America) | Fajr 15°, Isha 15° |
| Moonsighting Committee Worldwide | Fajr 18°, Isha 18°, seasonal |
| Egyptian General Authority of Survey | Fajr 19.5°, Isha 17.5° |
| Umm al-Qura, Makkah | Fajr 18.5°, Isha 90 min (120 Ramadan) |
| University of Islamic Sciences, Karachi | Fajr 18°, Isha 18° |
| Diyanet İşleri Başkanlığı (Turkey) | Diyanet approximation |
| Kemenag (Indonesia) | Fajr 20°, Isha 18°, ihtiyat |
| JAKIM (Malaysia) | Fajr 18°, Isha 18°, ihtiyati |
| MUIS (Singapore) | Fajr 20°, Isha 18° |
| UAE (Dubai) | Fajr 18.2°, Isha 18.2° |
| Qatar | Fajr 18°, Isha 90 min |
| Kuwait | Fajr 18°, Isha 17.5° |
| Morocco (Habous) | Fajr 19°, Isha 17° |
| Algeria | Fajr 18°, Isha 17° |
| Tunisia | Fajr 18°, Isha 18° |
| UOIF / Musulmans de France | Fajr 12°, Isha 12° |
| Spiritual Administration of Muslims of Russia | Fajr 16°, Isha 15° |
| Institute of Geophysics, Tehran | Fajr 17.7°, Isha 14°, Maghrib 4.5° |
| Shia Ithna Ashari (Leva Institute, Qum) | Fajr 16°, Isha 14°, Maghrib 4° |
Who uses which
| Method | Mainly used in |
|---|---|
| Muslim World League (18°/17°) | Europe, much of Africa and Asia, many general-purpose apps as a default |
| ISNA (15°/15°) | United States, Canada; endorsed by the Fiqh Council of North America |
| Moonsighting Committee (18°/18° with seasonal adjustment) | A growing number of North American and UK masjids |
| Egyptian General Authority (19.5°/17.5°) | Egypt, Syria, Iraq, Lebanon, Sudan, parts of Africa |
| Umm al-Qura (18.5°, Isha 90 min) | Saudi Arabia; also Bahrain and some Gulf timetables |
| University of Islamic Sciences, Karachi (18°/18°) | Pakistan, Bangladesh, India, Afghanistan |
| Diyanet | Turkey and Turkish communities abroad |
| Kemenag (20°/18° with ihtiyat) | Indonesia |
| JAKIM (18°/18° since 2020, with ihtiyati) | Malaysia |
| MUIS (20°/18°) | Singapore |
| Dubai, Qatar, Kuwait | Their own national timetables |
| Morocco, Algeria, Tunisia | National ministries, 18° to 19° Fajr |
| UOIF / Musulmans de France (12°/12°) | Some French mosques; a deliberately late Fajr and early Isha |
| Spiritual Administration of Muslims of Russia (16°/15°) | Russia |
| Tehran (17.7°/14°, Maghrib 4.5°) | Iran |
| Shia Ithna Ashari, Leva Institute (16°/14°, Maghrib 4°) | Shia communities outside Iran |
Within one country a masjid may still use a different method than the national default. The table is a starting point, not a rule.
Why Fajr can differ by 20 to 40 minutes
The sun does not drop straight down; it slides below the horizon at an angle that depends on your latitude. The further from the equator, the longer it takes to go from 15° to 18° below, so the gap between methods grows with latitude and with the season.
Real numbers for the expected first day of Ramadan, Monday 8 February 2027:
| City | 18° (MWL) Fajr | 15° (ISNA) Fajr | 12° (UOIF) Fajr | Gap 18° vs 15° |
|---|---|---|---|---|
| Cairo (30° N) | 05:20 | 05:34 | – | 14 min |
| New York (41° N) | 05:26 | 05:42 | – | 16 min |
| London (51.5° N) | 05:34 | 05:53 | 06:13 | 19 min |
In June the same London gap is 30 minutes or more, and above 48° an 18° dawn stops existing altogether in midsummer, which is why there is a separate article on high-latitude prayer times.
The Isha side behaves the same way in reverse: a larger angle makes Isha later. The Egyptian 17.5° and the MWL 17° Isha are within a few minutes; ISNA's 15° is 10 to 15 minutes earlier at mid-latitudes.
Why the angles were chosen
Each body picked its angle from observations of the sky in its own region, combined with the scholarly description of true dawn as a whiteness spreading along the horizon (Qur'an 2:187, the white thread) and of Isha as the disappearance of the red glow. In clear desert air the dawn band is seen earlier, which supports 18° to 20°; in humid or light-polluted places observers report it later, which supports 15°. Both camps are trying to match the same sky event. The Fajr and true dawn and Isha and shafaq articles go into the evidence without taking sides.
How to choose
- Follow your local masjid or national authority. If your mosque prints a timetable, match its method in the prayer times tool and your numbers will line up. Congregational prayer is the goal, and consistency within a community matters more than a few minutes either way.
- If there is no local standard, use your country's row in the table, or the Muslim World League as a broad default.
- Be a little careful with suhoor. If you are unsure between two methods in Ramadan, stopping at the earlier Fajr is the safer side for the fast. The imsak article explains how timetables build that in.
- Do not mix. Taking the earliest Fajr from one app and the earliest Isha from another produces a timetable no authority endorses.
- Do not switch methods to make Fajr later. Choose once, for a reason, and stay with it.
What does not depend on the method
Sunrise, Dhuhr, Asr (given the shadow rule) and Maghrib. If those differ between two sources for the same city, the cause is something else: coordinates, time zone, a few precaution minutes added by the masjid, or rounding. The mosque times vs apps article lists these causes one by one.
Whatever you choose, this is a matter on which qualified people have differed for a long time. Pick the method your community prays by, and for your own circumstances ask a scholar or imam you trust.
Useful tools
Questions and answers
Which calculation method is the most correct?
There is no single correct method. All of them agree on sunrise, Dhuhr, Asr and Maghrib. They differ on how dark the sky must be for Fajr and Isha, which is a question of observation and scholarly judgement. Follow the method your local masjid or national authority uses.
Why is my Fajr 30 minutes earlier than my friend's in the same city?
Almost certainly a different method. An 18° Fajr is about 20 minutes earlier than a 15° Fajr in winter at mid-latitudes, and 30 to 40 minutes earlier in summer. Compare the method setting in both apps.
Can I use Umm al-Qura outside Saudi Arabia?
You can, but its fixed 90-minute Isha was designed for Makkah's latitude. In northern Europe in summer 90 minutes after Maghrib may still be bright, and in winter it may be later than the real end of twilight. An angle-based method is more faithful to the sky elsewhere.
What does the method change in Ramadan?
Only two things in practice: suhoor must end at Fajr, so an earlier-Fajr method means an earlier end to eating, and in the Umm al-Qura method Isha is moved to 120 minutes after Maghrib during Ramadan to leave room for tarawih.
My country is not in the table. What do I pick?
Use the method of the religious authority your mosques follow, if any. Otherwise Muslim World League (18°/17°) is a widely accepted middle choice, and you can compare its Fajr with what your masjid prints.
Sources
- Qur'an 2:187
- Sahih Muslim 612 (times of the prayers)
- Published parameters of the Muslim World League, ISNA, Egyptian General Authority of Survey, Umm al-Qura University, University of Islamic Sciences Karachi, Diyanet, Kemenag, JAKIM, MUIS, UOIF and the Institute of Geophysics, Tehran, as implemented in the adhan library