Time Zones & Calendar Suite
High-precision astronomical, religious, business, and standardization calendar converters.
Islamic Hijri ↔ Gregorian Calendar
The Hijri calendar is a purely lunar calendar consisting of 12 months in a year of 354 or 355 days. Easily align Gregorian dates with Islamic lunar months, with support for regional astronomical sight adjustments.
Adjust by 1–2 days to match regional visual observations (e.g., Hilal sighting variations in North America, Saudi Arabia, or South Asia).
Dynamic Conversion Output
Calendar Insights
- • **Lunar Alignment**: Islamic calendars depend on physical lunar observations (hilāl). The Um Al-Qura calculation represents the official calendar of Saudi Arabia but variations occur based on geographic moon visibility.
- • **Year count**: Hijri year starts from the Hijra of Prophet Muhammad in 622 CE.
Explore Additional Utilities
Visual Acuity Converter
Convert visual acuity measurements between Snellen US (20/20), Snellen Metric (6/6), decimal, LogMAR, and Percentage systems.
Engineering Slope & Gradients
Compare elevation grades, percentage slopes, and corresponding degrees.
AWG Cable Sizer
Convert American Wire Gauge (AWG) sizes to metric dimensions, and estimate current carrying capacity.
No Claim Discount (NCD)
Track and project No Claim Discount percentages, claim-free year scales, and calculate potential premium savings with claim step-backs.
Clothing Size Converter
Convert apparel sizes (XS to 3XL) across US, UK, European, and Asian standards.
Frequency ↔ wavelength — antenna length calculation
Determine electromagnetic wavelength from frequency and velocity factors. Get recommended quarter-wave and half-wave antenna lengths.
Depth of Field (DoF) Calculator
Evaluate depth of field, near/far sharp limits, and circle of confusion based on sensor crop factor, focal length, aperture, and subject distance.
URL Slug Generator
Generate clean, hyphenated, SEO-friendly slugs from any string with custom separators.
Grout coverage — tile size ↔ joint width → bags needed
Estimate dry grout requirements based on tile dimensions, joint width, joint depth, and overall surface area.
Duration Converter
Convert time intervals seamlessly between weeks, days, hours, minutes, and seconds.
Fiscal Year ↔ Calendar Year Mapping
Map calendar months and dates to custom corporate Fiscal Years (FY) and quarters (Q1–Q4) with customizable fiscal start months.
Clinical Blood Pressure Gauges
Compare clinical medical blood pressure or vacuum values between mmHg and kPa units.
Data Storage Units
Convert digital storage capacity sizes across bits, Bytes, MB, GB, and Terabytes.
Magnetic Declination
Estimate compass alignment values and offset angles between magnetic north and true north.
Percentile ↔ z-score ↔ standard deviation
Determine z-scores, percentiles, standard deviation steps, and probability density for standard normal distribution curves.
Nutritional Energy (kcal ↔ kJ)
Convert food nutritional calories and physical kilojoules standard label indexes.
RAID capacity — disk count + size + type → usable space
Calculate usable capacity, parity overhead, and fault tolerance strategies for RAID 0, 1, 5, 6, and 10.
Wood moisture content ↔ shrinkage percentage
Calculate expected wood dimensional shrinkage (radial, tangential, volumetric) based on changes in wood moisture content below fiber saturation point.
Flash Guide Number Calculator
Solve the photography flash equation to find guide numbers, aperture, subject distance, or ISO speed for perfect manual flash exposures.
Length Converter
Convert between meter, kilometer, centimeter, mile, yard, foot, inch, and more.