Prayer Time Calculation Methods Explained: ISNA, MWL, and More

Why calculation methods matter

Prayer times are based on the position of the sun. Fajr begins at dawn, Dhuhr is when the sun passes its zenith, and Maghrib is at sunset. The math behind this is well established, but Islamic scholars and organizations differ on exactly how to define "dawn" and "night" for Fajr and Isha.

That is why there are multiple calculation methods. Each one uses a slightly different sun angle to determine when Fajr and Isha begin. The rest of the prayers (Dhuhr, Asr, Maghrib) are nearly identical across all methods.

The major calculation methods

ISNA (Islamic Society of North America)

• Fajr angle: 15 degrees
• Isha angle: 15 degrees
• Best for: United States, Canada

ISNA is the most widely used method in North America. It produces moderate Fajr and Isha times that work well for most latitudes in the US and Canada.

MWL (Muslim World League)

• Fajr angle: 18 degrees
• Isha angle: 17 degrees
• Best for: Europe, Far East, parts of the Americas

MWL uses a wider angle for Fajr, which means an earlier Fajr time compared to ISNA. Many mosques in Europe and Southeast Asia follow this method.

Egyptian General Authority of Survey

• Fajr angle: 19.5 degrees
• Isha angle: 17.5 degrees
• Best for: Africa, Syria, Iraq, Lebanon, Malaysia

This method produces the earliest Fajr times among the common methods. It is widely used across the Middle East and Africa.

Umm al-Qura (Saudi Arabia)

• Fajr angle: 18.5 degrees
• Isha: 90 minutes after Maghrib (fixed interval)
• Best for: Saudi Arabia, Gulf states

The Umm al-Qura method is unique because it uses a fixed interval for Isha rather than a sun angle. This is the official method used in Makkah and Madinah.

Karachi (University of Islamic Sciences)

• Fajr angle: 18 degrees
• Isha angle: 18 degrees
• Best for: Pakistan, Bangladesh, India, Afghanistan

This method is commonly followed in South Asia. Both Fajr and Isha use the same 18-degree angle.

Tehran (Institute of Geophysics)

• Fajr angle: 17.7 degrees
• Isha angle: 14 degrees
• Best for: Iran, some Shia communities

The Tehran method uses a narrower Isha angle, resulting in an earlier Isha time compared to most other methods.

What about Asr timing?

Asr timing is separate from the calculation method. There are two opinions:

• Shafi'i / Hanbali / Maliki: Asr begins when the shadow of an object equals its length (shadow factor of 1). This is the earlier Asr time.
• Hanafi: Asr begins when the shadow equals twice the object's length (shadow factor of 2). This is a later Asr time.

In AzanCast, you choose your madhab separately from the calculation method. This gives you the correct Asr time regardless of which overall method you use.

How to choose the right method

The simplest approach: follow your local mosque or Islamic organization. If your mosque uses ISNA, use ISNA. If they follow MWL, use MWL.

If you are unsure:

• In the US or Canada: ISNA is the most common choice
• In Europe: MWL or ISNA, depending on your community
• In the Middle East: Umm al-Qura (Gulf) or Egyptian (Levant/North Africa)
• In South Asia: Karachi
• In Southeast Asia: MWL or Egyptian

Fine-tuning with offsets

Sometimes your local mosque times do not match any standard calculation method exactly. Mosques often apply small adjustments, adding or subtracting a few minutes from individual prayers.

AzanCast supports per-prayer offsets, so you can match your local mosque times precisely. For example, if your mosque starts Fajr 2 minutes later than the calculated ISNA time, you can add a +2 minute offset to Fajr.

Setting up your calculation method in AzanCast

1. Log in to your AzanCast dashboard
2. Go to Settings
3. Choose your calculation method from the dropdown
4. Select your madhab for Asr timing
5. Add any per-prayer offsets if needed
6. Save your settings

Your Alexa will use these settings for every adhan going forward. If you ever switch mosques or move to a new city, just update the method and your prayer times adjust immediately.

Learn more

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