How Prayer Times Are Calculated

Prayer	Begins	Based on
Fajr (Dawn)	When the first light appears on the horizon before sunrise	Sun angle below the horizon (varies by method: 15°–19.5°)
Sunrise / Shurooq	When the upper edge of the sun appears above the horizon	Exact sunrise calculation (not a prayer, but marks the end of Fajr)
Zuhr / Dhuhr (Noon)	Shortly after the sun crosses the meridian (solar noon)	Sun at its highest point plus a small safety margin
Asr (Afternoon)	When an object's shadow reaches a certain length	Shadow equals object height (Shafi) or twice object height (Hanafi)
Maghrib (Sunset)	When the sun sets below the horizon	Exact sunset calculation
Isha (Night)	When the twilight (red glow) has fully disappeared	Sun angle below the horizon (varies by method: 15°–18°) or a fixed interval after Maghrib

Method	Fajr angle	Isha	Used in
ISNA (Islamic Society of North America)	15°	15°	USA, Canada
Muslim World League (MWL)	18°	17°	Global default, Europe
Egyptian General Authority	19.5°	17.5°	Egypt, parts of Africa
Umm al-Qura	18.5°	90 min after Maghrib*	Saudi Arabia, Gulf states
University of Karachi	18°	18°	Pakistan, Bangladesh, India
Tehran (Institute of Geophysics)	17.7°	14° + Maghrib angle 4.5°	Iran, Ja'fari communities
Moonsighting Committee	18°	18° + seasonal adjustments	UK, parts of North America
Singapore (MUIS - Majlis Ugama Islam Singapura)	20°	18°	Singapore, Southeast Asia

Your region	Method selected
Saudi Arabia, Gulf states, Iraq	Umm al-Qura
Iran	Tehran (Ja'fari)
Pakistan, India, Bangladesh, South Asia	University of Karachi
Singapore, Southeast Asia	Singapore (MUIS)
United Kingdom, Ireland	Moonsighting Committee
USA, Canada, Americas	ISNA (North America)
All other locations	Muslim World League (global default)

Section A: Astronomical Foundations

Prayer times are calculated using precise astronomical formulas based on the solar position. As the Earth rotates, the sun's position relative to a specific location changes throughout the day. The foundational metric used in these calculations is the solar zenith angle, which measures the angle of the sun relative to the vertical (directly overhead) at your specific location. When the sun is at its highest point in the sky, the zenith angle is zero, marking solar noon. As the sun descends toward the horizon, the zenith angle increases, and when it drops below the horizon, the angle exceeds 90 degrees.

A critical concept in this calculation is the difference between apparent solar noon and true solar noon. True solar noon is the exact moment the sun crosses the local meridian. However, because the Earth's orbit is elliptical and its axis is tilted, the sun's apparent movement across the sky is not perfectly uniform throughout the year. This variation is corrected using the Equation of Time, ensuring that Zuhr is calculated accurately regardless of the season.

Fajr and Isha times are determined by specific twilight angles. Twilight occurs when the sun is below the horizon, but its light scatters through the atmosphere. Islamic scholars define Fajr as the beginning of true dawn (morning astronomical twilight) and Isha as the disappearance of twilight (evening astronomical twilight). Different calculation methods use varying sun depression angles (how far below the horizon the sun must be) to define these moments, typically ranging between 15 and 19.5 degrees.

Latitude dramatically affects prayer times because the angle at which the sun rises and sets changes depending on how far north or south you are. Near the equator, the sun rises almost vertically, meaning twilight periods are very short. At higher latitudes, the sun rises and sets at a shallower angle, causing twilight periods to last much longer. This is why Fajr and Isha windows are significantly longer in cities like London compared to cities closer to the equator like Nairobi.

Altitude above sea level also affects calculations. At higher elevations, the horizon dips slightly, meaning an observer at altitude will see the sun rise earlier and set later than someone at sea level. While standard prayer time calculators often assume sea level for simplicity, advanced astronomical algorithms can adjust for altitude to provide times accurate to the minute in mountainous regions.

Section B: The Five Prayers In Depth

Understanding the spiritual and astronomical significance of each prayer helps in appreciating the precision of Islamic timings.

Fajr: The Pre-Dawn Prayer

Fajr begins at "true dawn," the moment when the first horizontal light appears on the eastern horizon. Astronomically, this corresponds to morning astronomical twilight. The spiritual significance of Fajr lies in beginning the day with remembrance before the distractions of the world begin. The timing logic requires the sun to be a specific number of degrees below the horizon (usually 15 to 19.5 degrees) to ensure the light is truly spreading across the horizon, not just a faint glow in the sky.

Zuhr: The Solar Noon Prayer

Zuhr begins shortly after the sun crosses the local meridian, reaching its highest point in the sky. This prayer marks the midpoint of the day. The daily shift in Zuhr time occurs because of the Earth's elliptical orbit and axial tilt, which cause the length of the solar day to vary slightly throughout the year. Historically and spiritually, Zuhr served as a time for rest and reflection in the heat of the day before resuming afternoon activities.

Asr: The Afternoon Prayer

Asr timing depends on the length of an object's shadow. This prayer clearly illustrates the difference between the Shafi and Hanafi schools of jurisprudence. The Shafi school dictates that Asr begins when an object's shadow equals its own length (plus the shadow it had at solar noon). The Hanafi school dictates that Asr begins when the shadow is twice the object's length. This difference results in the Hanafi Asr time being roughly 45 to 60 minutes later than the Shafi time, depending on the season and latitude.

Maghrib: The Sunset Prayer

Maghrib begins precisely at sunset. Astronomically, sunset is defined as the exact moment the upper edge of the sun's disk disappears below the true horizon. Visually, atmospheric refraction can make the sun appear to set slightly later than it actually does, but calculations rely on the true geometric position. Maghrib marks the end of the daytime fast during Ramadan and holds deep spiritual significance as the transition from day to night.

Isha: The Night Prayer

Isha begins when the twilight has fully disappeared and the sky is dark. Like Fajr, this is calculated using a specific sun depression angle below the horizon (typically 15 to 18 degrees). At extreme latitudes during summer months, the sun may never drop low enough below the horizon for twilight to completely disappear. In these circumstances, the angle required for Isha is never reached, necessitating alternative calculation methods to prevent Isha from overlapping with Fajr or occurring at impossible times.

Modern prayer time calculators use the sun's position relative to the horizon to determine when each prayer window opens. The key inputs are your geographic coordinates (latitude and longitude), the date, and the calculation method. The sun's declination angle and the equation of time are computed for the given date, and then trigonometric formulas determine the exact moment the sun reaches the required angle below the horizon.

Zuhr, Sunrise, and Maghrib are relatively straightforward as they correspond to solar noon, sunrise, and sunset. Fajr and Isha are more complex because they depend on the angle of twilight. Asr depends on shadow length, which varies by jurisprudential convention. This tool uses the open-source adhan.js astronomical library, which implements the standard prayer time equations used by major Islamic organisations worldwide.

Section C: Major Calculation Methods

Different Islamic authorities around the world have established their own parameters for calculating Fajr and Isha times. These methods differ primarily in the sun depression angles they use. A larger angle means an earlier Fajr and a later Isha.

Method	Fajr Angle	Isha Angle	Used In
Muslim World League (MWL)	18 degrees	17 degrees	Global default, Europe
ISNA (Islamic Society of North America)	15 degrees	15 degrees	USA, Canada
Egyptian General Authority	19.5 degrees	17.5 degrees	Egypt, parts of Africa
Umm Al-Qura University	18.5 degrees	90 min after Maghrib	Saudi Arabia, Gulf states
University of Islamic Sciences Karachi	18 degrees	18 degrees	Pakistan, Bangladesh, India

Because ISNA uses a 15 degree angle while the Egyptian method uses 19.5 degrees, Fajr under the Egyptian method can be 20 to 30 minutes earlier than under ISNA at the same location. This is the single biggest reason two prayer apps may show different Fajr times for the same city. When choosing the right method for your location, it is best to follow the convention used by your local mosque or national Islamic council. Our tool automatically selects the most appropriate method based on your geographic region.

How This Tool Selects Your Method

When you open this tool, it detects your geographic location and automatically selects the calculation method most commonly used in your region. You do not need to configure anything manually, but you can verify which method is being used in the information panel below the prayer times.

Note: If your local mosque or Islamic authority uses a different method, your times may differ by a few minutes. This is normal and all methods are valid scholarly conventions based on different interpretations of twilight observation.

Madhab Differences in Prayer Times

This tool supports three jurisprudential conventions for Asr and Maghrib timing. You can switch between them using the toggle buttons on the calculator page.

Shafi (also Maliki and Hanbali): Asr begins when the shadow of an object equals the length of the object itself (plus the shadow length at solar noon). This produces an earlier Asr time and is the default setting.
Hanafi: Asr begins when the shadow of an object equals twice the length of the object (plus the shadow length at solar noon). This produces an Asr time approximately 30 to 60 minutes later than the Shafi calculation.
Ja'fari (Fiqh Jafariya): Asr timing is similar to the Shafi convention. The main difference is in Maghrib, which is observed approximately 15 to 20 minutes after sunset when the redness has faded from the eastern sky.

Section D: Special Circumstances

Prayer times can be affected by external factors such as Daylight Saving Time (DST). When clocks move forward or backward by one hour, the local clock time for prayers shifts accordingly, even though the astronomical position of the sun has not changed. Calculators must accurately account for DST transitions to prevent times from being off by exactly one hour during part of the year.

Prayer times at extreme latitudes present a unique challenge. In cities far north or south (such as Oslo or Reykjavik) during summer, the sun may never set low enough for twilight to disappear, causing Fajr and Isha to overlap or not occur at all. The scholarly debate on this issue has led to several common solutions. Some methods suggest adopting the times of Mecca or Medina for these periods. Others recommend using the times of the nearest location where prayers are distinguishable, or calculating based on a fixed angle (such as 45 degrees) that ensures a practical time window.

High altitude considerations are also important. If you live in a mountainous region or a high-rise building, the horizon is lower for you than for someone at sea level. This means you will see the sun rise earlier and set later. While standard calculations assume sea level, some advanced tools apply altitude corrections to adjust sunrise and sunset by a minute or two.

When traveling across time zones, it is essential to update your location so the calculator can fetch the correct local time zone. Your device's internal clock combined with the local coordinates ensures that the prayer times displayed match the actual solar time of your destination.

What to do when Fajr and Isha overlap at high latitudes in summer months? In such cases, scholars generally advise following the closest reasonable calculation (such as the closest city where times do not overlap) or adopting a standard like half the night calculation, which divides the night between Maghrib and Fajr to establish a window for Isha.

Section E: Qibla Direction

The Qibla is the direction that Muslims face during prayer, specifically pointing toward the Kaaba in Mecca, Saudi Arabia. It matters because aligning oneself with the Qibla is a mandatory requirement for the validity of the prayer.

Qibla direction is calculated mathematically using the geographic coordinates of your location and the coordinates of the Kaaba. Because the Earth is a sphere, the shortest path between two points is a "great circle" route, not a straight line on a flat map. Calculating the Qibla involves spherical trigonometry to find the initial bearing from your location to Mecca along this great circle.

Because the Earth is curved, the Qibla varies by location. If you face southeast on a flat map in North America, you are actually pointing away from Mecca. The great circle route from North America to Mecca often goes over the North Pole or near it, meaning the correct Qibla direction is often Northeast, not Southeast.

Our calculator determines your Qibla direction by applying standard spherical trigonometry formulas to your detected latitude and longitude. It calculates the true bearing (angle from true North) to the Kaaba, allowing you to align yourself accurately for prayer.

Tahajjud, Ishraq, and Voluntary Prayers

In addition to the five obligatory prayers, many Muslims observe voluntary prayers at specific times. This tool shows estimated times for several of these. Tahajjud is the late-night voluntary prayer observed during the last third of the night. The tool calculates the night period (Maghrib to Fajr) and identifies the final third. Ishraq is a voluntary prayer observed approximately 15 to 20 minutes after sunrise, once the sun has risen well above the horizon.

Why Your Times Might Differ From Another App

If you have ever compared two prayer time apps and seen different results for the same city, you are not alone. The most common reasons are different calculation methods, different Asr jurisprudence, safety minutes (ihtiyat) added by mosques, altitude adjustments, Daylight saving time handling, and local mosque adjustments. All methods are valid scholarly conventions. If your local Islamic authority or mosque provides specific times, those take precedence.

Find estimated prayer times for your location

Section F: Frequently Asked Questions

Q1: Why do prayer times differ between apps?

Different apps use different calculation methods (such as ISNA vs. MWL) and different Asr conventions (Shafi vs. Hanafi). Even small differences in sun angle parameters can shift Fajr and Isha by 15 to 30 minutes. Some apps also add safety minutes (ihtiyat) that this tool does not include.

Q2: Which calculation method should I use?

You should use the method adopted by your local mosque or national Islamic authority. This tool automatically selects the most commonly used method for your region. You can check the information panel on the calculator page to see which method is applied.

Q3: How accurate are these times?

Prayer times are estimated using the same astronomical algorithms used by major Islamic organisations worldwide. They are generally within 1 to 2 minutes of other tools using the same method. However, local mosques may publish slightly different times due to safety minutes or regional conventions.

Q4: Why does Asr time vary?

Asr time varies primarily because of the difference between the Shafi and Hanafi schools of jurisprudence. The Shafi school begins Asr when an object's shadow equals its length, while the Hanafi school waits until the shadow is twice the object's length, resulting in a later time.

Q5: What happens to prayer times in Alaska or Norway?

At extreme latitudes, the sun may not set low enough below the horizon for twilight to disappear in summer. In these cases, scholars recommend alternative methods, such as adopting the times of the nearest location where prayers are distinguishable or using half the night calculation. Our tool applies automatic high-latitude adjustments.

Q6: How is Fajr different from sunrise?

Fajr begins at true dawn, when the first light appears horizontally on the horizon, while the sun is still below the horizon. Sunrise (Shurooq) occurs later, when the upper edge of the sun actually appears above the horizon. Fajr prayer must be completed before sunrise begins.

Q7: Can I use these times for fasting?

Yes, you can use the Fajr time to know when to stop eating (Sehri ends) and the Maghrib time to know when to break your fast (Iftar). However, it is always recommended to add a small safety margin before Fajr to ensure your fast is valid.

Q8: Why does my mosque use different times?

Your local mosque may apply a different calculation method, add safety minutes (ihtiyat), or make manual adjustments based on local visual sightings. Local authority times always take precedence over app calculations.

Q9: How does location permission work?

When you allow location access, your browser uses GPS or IP address to find your coordinates. These coordinates are used directly in your browser to calculate prayer times. The data is never sent to or stored on our servers.

Q10: Are these times suitable for all madhabs?

Yes, this tool supports Shafi, Hanafi, and Ja'fari conventions. You can toggle between them on the calculator page. The choice affects Asr timing and, in the Ja'fari tradition, Maghrib timing.

Sources: Astronomical calculations via adhan.js (Batoul Apps, open source). Calculation method parameters from ISNA, Muslim World League, Egyptian General Authority of Survey, Umm al-Qura University, University of Karachi, Institute of Geophysics (Tehran), Moonsighting Committee, and MUIS Singapore. Location data via OpenStreetMap / Nominatim. Shadow-length conventions per Shafi, Hanafi, and Ja'fari jurisprudence.

Understanding Prayer Times

How Prayer Times Work

The Five Daily Prayers

Fajr - The Dawn Prayer

Sunrise (Shurooq)

Zuhr / Dhuhr - The Noon Prayer

Asr - The Afternoon Prayer

Maghrib - The Sunset Prayer

Isha - The Night Prayer