How we calculate: Islamic Tools

Fajr/Isha are computed from the sun's position below the horizon (a named angle per method, or a fixed post-Maghrib interval for Umm al-Qura); Dhuhr is solar noon; Asr is when an object's shadow equals (Shafi'i) or doubles (Hanafi) its own length; Maghrib is sunset. Based on Jean Meeus' Astronomical Algorithms via the adhan library.

Calculation method and madhab are real, different conventions used by different regional Islamic authorities and schools of thought — not an implementation detail. Verified 2026-09-06: this tool's Umm al-Qura output lands Isha exactly 90 minutes after Maghrib, matching the officially documented Saudi standard.

• adhan (npm) — Islamic prayer times library implementing Jean Meeus' Astronomical Algorithms — accessed 2026-09-06
• Umm Al-Qura University calculation method — official Saudi Arabian standard — accessed 2026-09-06

Great-circle initial bearing formula (spherical trigonometry) from your coordinates to the Kaaba's fixed location (21.4225°N, 39.8262°E).

This is a great-circle (shortest real-world path over the globe) bearing, which is why it often doesn't point simply "east" or "west" the way a flat map might suggest — verified against commonly-cited reference bearings for New York City (~58°), London (~119°), and Jakarta (~295°). The bearing is relative to true north; using a physical compass requires separately accounting for magnetic declination at your location.

• Kaaba coordinates (21.4225°N, 39.8262°E) — commonly cited geographic reference — accessed 2026-09-06

Uses the Umm al-Qura tabular (arithmetic) Hijri calendar — a fixed 30-year leap-year cycle, not live moonsighting observations.

This is a calculated approximation, not local moonsighting announcements — the actual observed Islamic date in your country may differ by a day. Verified 2026-09-06 against a live Islamic-calendar site: correct month name, with exactly the expected ~1-day tabular-vs-sighting variance.

• hijri-converter (npm) — Umm al-Qura tabular Hijri/Gregorian conversion — accessed 2026-09-06

Each Gregorian day in the selected month is individually converted using the Umm al-Qura tabular Hijri calendar.

Same tabular-calculation caveat as the Hijri Date Converter: this may differ by a day from your local moonsighting-based calendar.

• hijri-converter (npm) — Umm al-Qura tabular Hijri/Gregorian conversion — accessed 2026-09-06

Finds the Hijri year whose 1 Muharram falls within the requested Gregorian year, using the Umm al-Qura tabular calendar.

This is a calculated approximation — the actual observed date depends on local moonsighting and may differ by a day.

• hijri-converter (npm) — Umm al-Qura tabular Hijri/Gregorian conversion — accessed 2026-09-06

Finds the Hijri year whose 1 Ramadan falls within the requested Gregorian year, using the Umm al-Qura tabular calendar.

This is a calculated approximation, not an official religious determination — the real start of Ramadan is announced by moon-sighting authorities and can differ by a day from this calculation, sometimes varying by country.

• hijri-converter (npm) — Umm al-Qura tabular Hijri/Gregorian conversion — accessed 2026-09-06

Finds the Hijri year whose 1 Shawwal falls within the requested Gregorian year, using the Umm al-Qura tabular calendar.

This is a calculated approximation — the real date is confirmed by moon sighting and may differ by a day, sometimes varying by country.

• hijri-converter (npm) — Umm al-Qura tabular Hijri/Gregorian conversion — accessed 2026-09-06

Finds the Hijri year whose 10 Dhu al-Hijjah falls within the requested Gregorian year, using the Umm al-Qura tabular calendar.

This is a calculated approximation — the real date (and the Hajj dates around it) is confirmed by Saudi Arabia's own moonsighting/lunar observation process and may differ by a day.

• hijri-converter (npm) — Umm al-Qura tabular Hijri/Gregorian conversion — accessed 2026-09-06

Nisab = 85 grams of gold, or 595 grams of silver (AAOIFI Shariah Standard No. 35) × the current live market price per gram.

Which standard to use is a genuine, unresolved scholarly split — silver gives a lower, more inclusive threshold; several contemporary scholars favor it for cash/mixed wealth, while others hold to the classical gold standard. This tool shows both rather than silently picking one.

• AAOIFI Shariah Standard No. 35 (Zakat) — nisab methodology — accessed 2026-09-06
• gold-api.com — free live gold/silver spot price API — accessed 2026-09-06

If savings ≥ nisab: Zakat due = savings × 2.5%. If savings < nisab: no Zakat is due.

Zakat on savings is due only if your wealth stayed at or above nisab for a full lunar (Hijri) year (hawl) — not just on the day you check, though this tool only evaluates the single amount you enter.

• AAOIFI Shariah Standard No. 35 (Zakat) — accessed 2026-09-06

If portfolio value ≥ nisab: Zakat due = value × 2.5%.

This calculates Zakat on full market value, the method most commonly applied to actively-traded stocks. Shares held long-term for dividends/growth have a genuinely different, more precise method some scholars recommend instead (Zakat only on your share of the company's own zakatable assets) — this tool can't compute that without the company's balance sheet, so it's disclosed rather than silently applied.

• AAOIFI Shariah Standard No. 35 (Zakat) — accessed 2026-09-06

No single authoritative Hajj cost figure exists — it depends heavily on your home country (some governments subsidize Hajj travel significantly) and Saudi Arabia's own Nusuk-platform package tier (Standard/Premium/Luxury). These ranges are illustrative, from real 2026 travel-industry reporting, not a fixed quote.

• Nusuk — Saudi Arabia's official Hajj/Umrah platform (package tiers) — accessed 2026-09-06

Required monthly savings = (target cost − already saved) ÷ months remaining.

Based on the same illustrative Hajj cost ranges as the Hajj Cost Calculator — actual costs vary by season and operator, so treat the result as a starting savings target, not a fixed number. Hajj is only religiously obligatory once, for those who are financially and physically able (istita'ah) — this tool doesn't assess ability, only estimates a savings plan for a cost you provide.

• Nusuk — Saudi Arabia's official Hajj/Umrah platform (package tiers) — accessed 2026-09-06

Umrah is significantly cheaper and shorter than Hajj. Cost depends on hotel class, room sharing, flight timing, and season — Ramadan and peak-season pricing runs notably higher than off-peak months. These ranges are illustrative, from real 2026 travel-industry reporting for a US departure — your home country's own pricing may differ.

• Real 2026 Umrah package pricing (US departure) — travel-industry reporting — accessed 2026-09-06

Quranic fixed shares (spouse 1/4 or 1/8, parents 1/6 each) are allocated first, then sons and daughters split the remaining residue in a 2:1 ratio — unless there are daughters with no sons, in which case daughters take a fixed share (1/2 for one, 2/3 for two or more) instead, with any leftover going to a surviving father.

Deliberately does not compute cases with NO surviving children — real research found a specific named classical exception (the "Umariyyatan" ruling) for certain spouse-and-parent combinations with genuinely conflicting figures even across authoritative sources, and siblings, grandparents, and more distant relatives aren't modeled at all. 'Awl (proportional reduction when fixed shares would exceed the whole estate) IS handled and was verified against a real classical textbook example (husband + father + mother + one daughter) before shipping.

• Islamic inheritance (Faraid) computerization research — academic reference for the rules-based approach — accessed 2026-09-06

Total payable = cost + profit margin (fixed, agreed at signing). Monthly payment = total payable ÷ number of months.

The profit margin is fixed at contract signing and never compounds, unlike conventional interest — the total payable is the same regardless of how long the repayment schedule runs.

• AAOIFI Shariah Standard No. 8 (Murabaha) — accessed 2026-09-06

Each month: rent = bank's remaining ownership share × (annual rate ÷ 12); buyout = (property value − down payment) ÷ total months (constant). Payment = rent + buyout; the bank's share is reduced by the buyout amount each month.

Modeled with a straight-line (equal-dollar) buyout each month — one defensible way to structure this, among a few real variations banks use. Monthly payments genuinely decrease over the term as the bank's share (and the rent on it) shrinks, unlike a conventional level-payment mortgage.

• AAOIFI Shariah Standard No. 12 (Sharikah/Musharakah, incl. Diminishing Musharakah) — accessed 2026-09-06

Same as Diminishing Musharakah: monthly rent on the bank's remaining share, plus a constant buyout installment.

Real Islamic banks may structure a home-financing product slightly differently (e.g. a non-linear buyout schedule) — always get your bank's actual amortization table rather than relying solely on this illustrative model.

• AAOIFI Shariah Standard No. 12 (Sharikah/Musharakah, incl. Diminishing Musharakah) — accessed 2026-09-06

Same as Murabaha: total payable = car price + fixed agreed profit margin, split evenly across the term.

Real Islamic car-finance products may also use Ijara (lease) structures at some institutions — check which structure your specific lender's product actually uses.

• AAOIFI Shariah Standard No. 8 (Murabaha) — accessed 2026-09-06

Monthly rent = asset value × annual rental rate ÷ 12. Total paid = monthly rent × number of months.

This models plain Ijara — a straightforward lease with no ownership build-up. Ijara Muntahia Bittamleek, a related hybrid ending in ownership transfer through a separate gift or sale, is a more complex variant this simpler model doesn't cover.

• AAOIFI Shariah Standard No. 9 (Ijarah and Ijarah Muntahia Bittamleek) — accessed 2026-09-06

Conventional: standard amortization formula (compounding monthly interest). Murabaha: (amount + fixed profit margin) ÷ months.

These aren't automatically equivalent — which costs less depends entirely on the specific rate and margin each option actually offers, not on the financing type itself. Enter your own real quotes to compare fairly, not assumed "typical" numbers.

• AAOIFI Shariah Standard No. 8 (Murabaha) — accessed 2026-09-06

Mahr al-Fatimi = 1,487.5g of silver (500 dirhams) × the current live silver price. Muqaddam = agreed amount × prompt %; Mu'akhkhar = agreed amount − Muqaddam.

Mahr has no fixed or required amount in Islamic law — Mahr al-Fatimi (traditionally cited as given to Fatimah bint Muhammad) is shown only as a commonly-referenced benchmark, not a minimum, maximum, or ruling.

• gold-api.com — free live gold/silver spot price API — accessed 2026-09-06

Non-menstruating divorced woman: start date + 3 lunar (Hijri) months (Quran 65:4). Widow, not pregnant: start date + 4 lunar months + 10 days (Quran 2:234).

Two real cases — a menstruating divorced woman (3 menstrual cycles) and a pregnant woman (until delivery) — have no fixed calendar length by explicit Quranic wording (65:4, 2:228), so this tool deliberately shows no computed date for them rather than fabricate one.

• Quran 65:4 and 2:234 — Iddah duration — accessed 2026-09-06

Boy: birth date + 7 years. Girl: birth date + 9 years (ordinary calendar years, the age of tamyiz/discernment per Abu Hanifah).

This shows one specific school's (Hanafi) traditional default only — other schools set genuinely different ages, some tying it to the child's own choice rather than a fixed age at all — and in practice, the family law of the country you live in almost always governs the actual legal custody outcome, not classical fiqh directly.

• Custody (Al-Hadanah) according to the five Islamic schools of jurisprudence — comparative fiqh reference — accessed 2026-09-06

Birth date + 24 lunar (Hijri) months (Quran 2:233, "two complete years").

This period is most significant for milk-kinship (radaa) rulings — nursing within it can establish a marriage-prohibited relationship under conditions scholars specify. It is not medical advice on how long to breastfeed, and the same verse explicitly permits weaning earlier by mutual parental consent.

• Quran 2:233 — the full breastfeeding period — accessed 2026-09-06

Total Fidya = missed days × staple food weight per day (kg) × price per kg.

The exact per-day weight is genuinely disputed — commonly cited figures range from about 1.5kg to 2kg of wheat/rice (or its cash value) depending on school and local fatwa council, so it's an adjustable input here rather than a silently fixed number. Fidya applies only when recovery isn't expected (old age, a chronic illness); if recovery is expected, the fast must instead be made up later (qada).

• Fidya for missed Ramadan fasts — practical calculation guidance — accessed 2026-09-06

Total = 60 people × staple food weight per person (kg) × price per kg.

Kaffarah follows a strict order: fast 2 consecutive months first, and only if genuinely unable, feed 60 poor people instead (this tool covers the feeding option only) — freeing a slave, the classical first option, no longer applies. It applies only to deliberately breaking a fast without a valid excuse, not to a fast missed for a genuine reason (illness, travel, menstruation), which requires only qada (making up the day later).

• Fidyah and Kaffarah — obligatory religious debts, practical guidance — accessed 2026-09-06

Annual distribution = principal × return rate. The principal itself is never spent.

This is a straightforward perpetuity calculation, not a religious computation — the actual return you'll earn depends entirely on how the principal is invested. A real waqf's terms and Shariah-compliant investment structure should be set up with a qualified scholar and financial advisor, not this tool alone.

• AAOIFI Shariah Standard No. 33 (Waqf) — endowment principles — accessed 2026-09-06

Fasting duration = Maghrib time − Fajr time, both computed astronomically for the given coordinates and date (same engine as this site's Prayer Times Calculator).

Fasting hours shift by a few minutes depending on the calculation method chosen — a genuine regional-authority difference, not a bug — and change day to day and by latitude as Fajr/Maghrib times shift through the year.

• adhan — astronomical prayer-time calculation library (Jean Meeus' algorithms) — accessed 2026-09-06

Total rakat = nights × (rakat per night + 3 if Witr is included).

Both 8-rakat and 20-rakat Tarawih are real, practiced traditions — 20 is the historically dominant practice (especially in the Hanafi school), while 8 is also cited from some reports of the Prophet's own practice. Neither is a universal requirement; this is a simple counting tool, not a ruling on which count is correct.

• Custody, prayer, and Ramadan-practice comparative fiqh references — accessed 2026-09-06

Uses astronomy-engine's SearchMoonPhase to find the next moment the Moon's ecliptic longitude relative to the Sun equals 0° (exact conjunction).

A new Islamic month traditionally begins with an actual crescent (hilal) sighting, which happens roughly a day or more AFTER conjunction and depends on the observer's location and local visibility — genuinely not computable from astronomy alone. This tool intentionally shows only the conjunction moment, not a predicted sighting date.

• astronomy-engine — VSOP87-based astronomical calculation library — accessed 2026-09-06

Each candidate date is the tabular Hijri-calendar equivalent of Ramadan (21/23/25/27/29) for the given Gregorian year.

The Quran (97) states Laylatul Qadr falls within the last ten nights of Ramadan but doesn't specify which — scholars differ on the most likely night, with the 27th commonly emphasized in some traditions but not universally agreed as certain. All 5 candidates are shown rather than a single date, since presenting one as definitive would misrepresent a real scholarly difference.

• Quran 97 (Surah Al-Qadr) — accessed 2026-09-06

The 99 Names themselves are a fixed, universally-recognized list (Quran 7:180) — cross-checked against a published reference before being used here, unlike some other content in this vertical which involves genuine scholarly disagreement.

• The 99 Names of Allah — published reference list — accessed 2026-09-06