Ramadan Calendar Calculator
Calculate Suhoor, Fajr, Maghrib, and Iftar times for any location during Ramadan. Get fasting duration and daily schedule based on your coordinates.
Ramadan Calendar Calculator
Calculator
Adjust values & calculateEnter your values below. Every result is computed in your browser — no data is sent to any server.
Formula: Fajr = Solar Noon − (1/15) × arccos[(sin(-18°) − sin(lat)sin(dec)) / (cos(lat)cos(dec))]
Worked example — Suhoor ends: ~5:00 AM | Iftar: ~6:22 PM | Fast: ~13h 10min
Formula
Fajr = Solar Noon − (1/15) × arccos[(sin(-18°) − sin(lat)sin(dec)) / (cos(lat)cos(dec))]
Prayer and fasting times are calculated using the sun's position. Fajr (dawn) occurs when the sun is 18° below the horizon. Maghrib (sunset) occurs at the geometric sunset. These depend on latitude, longitude, day of year, and the sun's declination.
Worked Examples
Example 1: Fasting Schedule in Makkah (Day 1 of Ramadan)
Problem:Calculate Suhoor and Iftar times for Makkah (lat 21.42°N, lng 39.83°E, UTC+3) on the first day of Ramadan.
Solution:Solar declination for ~March 18: ~-1.5° Fajr angle: -18° below horizon Fajr (Suhoor end): ~5:10 AM Sunrise: ~6:15 AM Maghrib (Iftar): ~6:20 PM Fast duration: ~13 hours 10 minutes
Result:Suhoor ends: ~5:00 AM | Iftar: ~6:22 PM | Fast: ~13h 10min
Example 2: Fasting Schedule in London (Day 15 of Ramadan)
Problem:Calculate fasting times for London (lat 51.51°N, lng -0.13°W, UTC+0) on day 15 of Ramadan (~early April).
Solution:Solar declination for ~April 1: ~4.5° Fajr at 51.5°N latitude: ~4:30 AM Sunrise: ~6:30 AM Maghrib: ~7:40 PM Fast duration: ~15 hours 10 minutes Note: London fasting hours are longer due to higher latitude
Result:Suhoor ends: ~4:20 AM | Iftar: ~7:42 PM | Fast: ~15h 10min
Frequently Asked Questions
How are Suhoor and Iftar times calculated?
Suhoor and Iftar times are calculated based on the position of the sun relative to the horizon at your specific geographic location. Suhoor (the pre-dawn meal) ends at Fajr time, which is when the sun is approximately 18 degrees below the eastern horizon (astronomical twilight begins). Many scholars recommend stopping eating 10-15 minutes before Fajr as a precaution. Iftar (the meal to break the fast) begins at Maghrib time, which is when the sun fully sets below the western horizon. Some communities add a 1-3 minute delay after sunset as a safety margin. The exact times vary daily because the sun's path changes throughout the month, and they differ significantly by geographic location and time of year.
Why do fasting hours vary by location during Ramadan?
Fasting hours vary dramatically by location because they depend on geographic latitude. Near the equator, day length remains relatively constant at about 12 hours year-round, resulting in consistent fasting durations of approximately 12-13 hours. At higher latitudes, day length varies greatly with the seasons. When Ramadan falls in summer months at northern latitudes, fasting can last 18-20 hours (as in Scandinavia or northern Canada). Conversely, when Ramadan occurs in winter at these locations, fasting might only be 8-9 hours. Locations very close to the poles may experience perpetual daylight or darkness, in which case Islamic scholars generally advise following the times of the nearest city with distinguishable day and night, or following Makkah's times.
What is the Islamic ruling on fasting at extreme latitudes?
At extreme latitudes (above 60 degrees) where the sun may not set or rise for extended periods, Islamic scholars have provided several opinions. The majority opinion from the Islamic Fiqh Council is to follow the prayer and fasting times of the nearest city where day and night are clearly distinguishable. Another scholarly opinion suggests following the times of Makkah al-Mukarramah, since it is the mother of all cities in Islamic tradition. A third opinion allows following the last normal day-night cycle before continuous daylight or darkness began. The European Council for Fatwa and Research recommends that Muslims in these areas should follow the nearest country where fasting hours are manageable, typically defined as having distinct dawn and dusk within a 24-hour period.
How does the Ramadan calendar shift each year?
Ramadan shifts approximately 10 to 11 days earlier each year on the Gregorian calendar because the Islamic calendar is a lunar calendar with 354 or 355 days per year, compared to the 365 or 366 days in the Gregorian solar calendar. This means Ramadan cycles through all seasons over approximately 33 years. In summer months, fasting hours are longer in the Northern Hemisphere, while in winter they are shorter. The exact start date of Ramadan is determined either by the physical sighting of the new crescent moon (hilal) or by astronomical calculations, depending on the methodology followed by different Muslim communities and countries. This is why the start date may differ by one or two days between regions.
What is the difference between Fajr angle methods used worldwide?
Different Islamic organizations use different sun depression angles for calculating Fajr time, which affects when fasting begins. The Muslim World League uses 18 degrees below the horizon for Fajr and 17 degrees for Isha. The Egyptian General Authority of Survey uses 19.5 degrees for Fajr and 17.5 degrees for Isha. The Islamic Society of North America (ISNA) uses 15 degrees for both Fajr and Isha. The University of Islamic Sciences, Karachi uses 18 degrees for Fajr and 18 degrees for Isha. The Umm al-Qura method used in Saudi Arabia uses a fixed 18.5 degrees for Fajr. These differences can result in Fajr times varying by 15-30 minutes between methods at the same location, which is why Muslims should follow the convention adopted by their local Islamic authority.
Why does the fasting duration change from the first day of Ramadan to the last?
Solar declination moves through the month, so Fajr creeps earlier and Maghrib later, or the reverse, depending on the season and hemisphere. Near an equinox the day length changes fastest, and the further you are from the equator the larger the daily step: it can be a minute or so per day in the tropics and several minutes per day at northern European latitudes. Over thirty days that accumulates into a noticeable difference, which is why the schedule table shows the first and last days rather than a single fixed duration.
Why is Ramadan sometimes 29 days and sometimes 30?
A synodic lunar month — new moon to new moon — averages about 29.53 days, so no whole number fits it. Islamic months therefore run 29 or 30 days, resolved by whether the crescent is sighted on the evening of the 29th. If it is, the new month begins; if not, the current month completes 30 days. Ramadan Calendar Calculator assumes a 30-day frame and lets you select a day within it, so if your community declares Eid after 29 days, the final row simply does not apply.
What is imsak, and why do timetables print it as a separate column?
Imsak is a precautionary marker placed a few minutes before Fajr, printed as its own column so that the true start of the fast, which is Fajr itself, stays visible beside it. Several scholars caution against treating that column as binding, precisely because a reader who abstains from that line onward can come to believe the fast begins there rather than at dawn. Timetables differ on the interval because it is a local convention rather than a fixed ruling, which is why Ramadan Calendar Calculator exposes it as an editable input.
Why is the Maghrib time here a few minutes earlier than my local timetable?
This tool computes geometric sunset, the moment the sun's centre crosses the horizon plane. Observed sunset comes slightly later because atmospheric refraction lifts the image of the sun and because the upper limb of the disc remains visible after the centre has set — together adding about 50 arcminutes of altitude, five-sixths of a degree: roughly 34 arcminutes of refraction plus the sun's 16-arcminute semi-diameter. That typically puts observed sunset three to four minutes after the geometric moment at Makkah's latitude and five or more at London's. Elevation matters too: from a high floor or a hilltop the sun sets measurably later than at ground level. Add the iftar delay input to reconcile the figure with a published timetable rather than assuming one is wrong.
How should I set the UTC offset if my country changes clocks during Ramadan?
The offset field converts the underlying solar calculation, which is done in UTC, into your wall-clock time, so it must match the offset actually in force on the day you are checking. Several Muslim-majority and European countries shift by an hour partway through the spring, and a few have historically suspended or reinstated the change specifically for Ramadan. If your clocks move mid-month, recompute the later days with the new offset; every printed time will shift by exactly that hour while the fast duration itself stays unchanged.
References
Reviewed for accuracy by Daniel Agrici, Founder & Lead Developer · Editorial policy
Related Calculators
🧮Afghan Solar Calendar Converter
Calculate afghan solar calendar converter with inputs, formulas, and instant results.
🧮Ramadan Fasting Hours Calculator
Calculate fasting hours from dawn to sunset for any location and date during Ramadan.
🧮Islamic Mortgage Calculator — Murabaha & Ijara
Calculate islamic mortgage with inputs, formulas, and instant results.
🧮Islamic Inheritance Calculator
Calculate islamic inheritance with inputs, formulas, and instant results.
🧮Islamic Date Calculator
Calculate days between two Hijri dates or convert Hijri date ranges to Gregorian.
🧮Islamic Will Calculator
Calculate Islamic inheritance shares (faraid) for all heirs according to Quran and Sunnah.
🧮Islamic Months Calculator
Convert between Hijri month names, numbers, and corresponding Gregorian date ranges.
🧮Zakat Calculator
Calculate zakat with inputs, formulas, and instant results.