Prayer Time Calculation Methods Compared: MWL, ISNA, Karachi
If you have ever compared two prayer apps and found that Fajr differs by 15 or 20 minutes, you have met the calculation methods. They are not mistakes. They are different, well-established ways of defining the start of Fajr and the start of Isha.
What the methods agree on
All methods use the same position of the sun for sunrise, solar noon and sunset, so Dhuhr and Maghrib are essentially the same everywhere (some authorities add a few minutes of caution). The real differences are the depression angle of the sun used for Fajr and for Isha, and how Isha is defined in a few methods.
The main methods
| Method | Fajr | Isha | Commonly used in |
|---|---|---|---|
| Muslim World League | 18° | 17° | Europe, the Far East, parts of the Americas |
| ISNA | 15° | 15° | North America |
| Egyptian General Authority of Survey | 19.5° | 17.5° | Egypt, Syria, Iraq, Lebanon, parts of Africa |
| University of Islamic Sciences, Karachi | 18° | 18° | Pakistan, India, Bangladesh, Afghanistan |
| Umm al-Qura University, Makkah | 18.5° | 90 minutes after Maghrib | Saudi Arabia and the Arabian Peninsula |
| Gulf Region | 18.2° | 18.2° | United Arab Emirates |
| Kuwait | 18° | 17.5° | Kuwait |
| Qatar | 18° | 90 minutes after Maghrib | Qatar |
| Singapore / Southeast Asia | 20° | 18° | Singapore, Indonesia, Brunei |
| Turkey (Diyanet style) | 18° | 17° | Turkey |
| University of Tehran | 17.7° | 14° | Iran, some Shia communities |
How big is the difference?
The sun moves roughly one degree every four minutes near the equator, and more slowly across the horizon at higher latitudes, so each degree of angle can mean 4 to 8 minutes. A 3° difference between the ISNA (15°) and the Muslim World League (18°) Fajr angles therefore shifts Fajr by roughly 12 minutes near the equator and often 20 to 30 minutes at mid-latitudes, with the later time for the smaller angle. Isha varies similarly.
Why do the angles differ?
The difference comes from how scholars and observatories interpret true dawn and the end of twilight, and from field observations made in different climates. Clear desert skies show dawn differently from humid or polluted skies. Several institutions have run observation studies and reached different angle estimates, and each community adopted the one it trusts. Some communities also prefer a slightly later Fajr and earlier Isha as a matter of caution or ease.
Fixed-interval Isha
Umm al-Qura and Qatar do not use an angle for Isha. They set Isha a fixed time after Maghrib (90 minutes). This is simple to publish and follows a long-standing practice in the region, but it means Isha does not track the actual end of twilight as the seasons change.
How to choose
- If your local mosque or religious authority publishes a timetable, choose the method that matches it.
- If not, use the default for your country, which is the method most people near you already follow.
- If you are in the West, check what your community's mosque uses before comparing apps; North American mosques often follow ISNA, while many European ones follow the Muslim World League or the local mosque's calendar.
On every prayertim.com timetable you can open the Options box and switch method instantly, and our methodology page lists the default for each country. For the high-latitude special case read prayer times at high latitudes.