Equatorial & Alt-Az Coordinates Converter
Convert Right Ascension to Hour Angle and compute real-time Altitude & Azimuth positions.
Hour Angle (HA) = LST − RA. Altitude is computed via spherical trigonometry: sin(Alt) = sin(Dec)sin(Lat) + cos(Dec)cos(Lat)cos(HA). Compass direction is then derived using spherical azimuth conversions.
Explore Additional Utilities
Oven Temperature & Gas Marks
Convert oven temperature heat indexes between Celsius, Fahrenheit, and official Gas Marks.
Fault slip rate — mm per year ↔ recurrence interval
Determine earthquake return recurrence intervals based on tectonics fault slip rates.
De Broglie wavelength — particle mass + velocity → wavelength
Calculate quantum mechanical wavelengths for matter waves under both classical and relativistic velocities.
Kiln temperature — cone number ↔ degrees Celsius
Map pyrometric Orton cones to exact kiln temperature equivalents at fast or slow heating rates.
Gear ratio ↔ final drive speed — RPM at given speed
Calculate vehicle road speed or engine RPM based on transmission gear ratios, final drive axle ratio, and tire dimensions.
Planck units ↔ SI units — fundamental physics constants
Translate between SI physical units and the fundamental Planck natural units based on universal constants.
Thermohaline density — temperature + salinity → seawater density
Determine seawater density and specific volume from water temperature and salinity using the UNESCO International Equation of State.
Flesch-Kincaid Reading Level
Calculate readability scores and Flesch-Kincaid school grade levels for any input text in real-time.
IQ score ↔ percentile rank
Map IQ scores (with standard deviations 15 or 16) to cognitive percentile ranks, rarity indices, and standard intelligence brackets.
Thread Weight Converter
Convert between different thread sizing standards including Tex, Denier, and Number English (Ne).
True wind ↔ apparent wind
Calculate apparent wind speed and angle from true wind speed, sailing angle, and boat speed (or vice versa).
Drug Concentration Converter
Convert pharmaceutical concentrations between % w/v, mg/mL, and mol/L using substance molecular weight presets.
Chisel bevel angle — degrees ↔ sharpening guide setting
Calculate chisel bevel angles and determine the exact projection distance needed for hone sharpening guides.
Clay shrinkage — wet size ↔ fired size
Calculate wet, bone-dry, and kiln-fired pottery dimensions and analyze total contraction rates.
Brood frame count ↔ colony population estimate
Convert frame counts of capped brood to estimate total emerging colony population and overall workforce strength.
Encoder resolution (PPR ↔ degrees per pulse)
Convert between encoder Pulses Per Revolution (PPR), Cycles Per Revolution (CPR), and angular resolution down to arcseconds.
Layer height ↔ print time estimator
Estimate 3D print duration changes and total layer counts when switching layer heights and print speeds.
International Hat Size Matcher
Convert hat dimensions across US, UK, and European standards.
MAC address formats — colon ↔ hyphen ↔ Cisco notation
Convert physical MAC addresses between IEEE colon, hyphen, Cisco dot format, and raw hex strings.
Void Fill Material Volume
Calculate empty space volume inside a shipping box after placing items to determine packaging material needed.