For the complete documentation index, see llms.txt.

84 endpoints

Science API

Same bearer token, same credit pool, same JSON envelope as every other endpoint — drop them into apps, sites, workflows, or agents without rebuilding formulas, validation, or docs.

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Astronomy

Astronomical Unit Converterastronomical-unit-converter

Convert astronomical distances among AU, light-time, parsecs, kilometers, and miles.

1cr · v2026-04-22

Chemical Calculators

Dilution Calculatordilution-calculator

Solve M1V1 = M2V2 for stock concentration, stock volume, final concentration, or final volume.

1cr · v2026-04-22

Empirical Formula Calculatorempirical-formula-calculator

Empirical formula from element mass percentages or masses, with optional molecular formula when a molecular mass is supplied.

1cr · v2026-04-22

Molality Calculatormolality-calculator

Calculate molality and colligative freezing and boiling point shifts.

1cr · v2026-04-22

Molar Mass Calculatormolar-mass-calculator

Molar mass of a chemical formula with per-element atom count, contribution, and percentage composition, supporting nested parentheses.

1cr · v2026-04-22

Molarity Calculatormolarity-calculator

Calculate molarity, solute mass, or solution volume from mass, molar mass, and volume.

1cr · v2026-04-22

Mole/Gram/Particle Convertermole-gram-particle-converter

Convert among moles, grams, and particles using molar mass and Avogadro's constant.

1cr · v2026-04-22

Nernst Equation Calculatornernst-equation-calculator

Calculate electrochemical cell potential under non-standard conditions.

1cr · v2026-04-22

Osmotic Pressure Calculatorosmotic-pressure-calculator

Calculate osmotic pressure from molarity, temperature, and van't Hoff factor.

1cr · v2026-04-22

pKa to Ka Converterpka-to-ka-converter

Convert between pKa, Ka, pKb, and Kb for an acid-base conjugate pair.

1cr · v2026-04-22

Chemistry

Beer-Lambert Law Calculatorbeer-lambert-law-calculator

Solve A = epsilon l c for absorbance, molar absorptivity, concentration, or path length.

1cr · v2026-04-22

Boiling Point Elevation Calculatorboiling-point-elevation-calculator

Calculate boiling point elevation from molality, Kb, and van't Hoff factor.

1cr · v2026-04-22

Freezing Point Depression Calculatorfreezing-point-depression-calculator

Freezing point depression (delta-Tf = i * Kf * m) from molality or from solute/solvent mass, with a van't Hoff factor for ionic solutes.

1cr · v2026-04-22

Henderson-Hasselbalch Calculatorhenderson-hasselbalch-calculator

Buffer pH from pKa and the conjugate base/acid ratio, or solve for the ratio or the pKa, via the Henderson-Hasselbalch equation.

1cr · v2026-04-22

Percent Yield Calculatorpercent-yield-calculator

Solve percent yield, actual yield, or theoretical yield.

1cr · v2026-04-22

pH Calculatorph-calculator

pH, pOH, [H+], and [OH-] from any one of them, with acidity classification at 25 C.

1cr · v2026-04-22

Electrical

Parallel Resistor Calculatorparallel-resistor-calculator

Calculate equivalent resistance and current sharing for resistors in parallel.

1cr · v2026-04-22

Power Factor Calculatorpower-factor-calculator

Calculate power factor, reactive power, or capacitor correction values.

1cr · v2026-04-22

RC Time Constant Calculatorrc-time-constant-calculator

Calculate RC circuit time constant, cutoff frequency, and charging or discharging levels.

1cr · v2026-04-22

Electronics

555 Timer Calculator555-timer-calculator

Calculate 555 timer astable frequency, period, duty cycle, or monostable pulse width.

1cr · v2026-04-22

Capacitor Calculatorcapacitor-calculator

Calculate capacitor charge, stored energy, reactance, RC timing, or decode ceramic capacitor codes.

1cr · v2026-04-22

Decibel (dB) Calculatordecibel-db-calculator

Calculate power dB, voltage dB, dB ratios, and dBm/dBW/watt conversions.

1cr · v2026-04-22

Ohm's Law Calculatorohm-s-law-calculator

Calculate voltage, current, resistance, and power from any two known values.

1cr · v2026-04-22

Parallel Capacitor Calculatorparallel-capacitor-calculator

Calculate equivalent capacitance for capacitors in parallel.

1cr · v2026-04-22

Resistor Color Code Calculatorresistor-color-code-calculator

Calculate 4-band, 5-band, and 6-band resistor values from color bands.

1cr · v2026-04-22

Resonant Frequency Calculatorresonant-frequency-calculator

Calculate LC/RLC resonant frequency, inductance, capacitance, impedance, Q factor, and bandwidth.

1cr · v2026-04-22

Series Resistor Calculatorseries-resistor-calculator

Calculate equivalent resistance for resistors in series.

1cr · v2026-04-22

Fluid Mechanics

Bernoulli Equation Calculatorbernoulli-equation-calculator

Solve one Bernoulli streamline pressure, velocity, or height term.

1cr · v2026-04-22

Reynolds Number Calculatorreynolds-number-calculator

Reynolds number with laminar/transitional/turbulent classification using geometry-specific thresholds for pipes, plates, and channels.

1cr · v2026-04-22

Mechanics

Belt Length Calculatorbelt-length-calculator

Calculate open or crossed belt length, wrap angles, and optional belt speed.

1cr · v2026-04-22

Bolt Torque Calculatorbolt-torque-calculator

Recommended bolt tightening torque and preload for metric sizes and ISO grades, by the short-form K method and VDI 2230.

1cr · v2026-04-22

Gear Ratio Calculator (Mechanical)gear-ratio-calculator-mechanical

Calculate gear ratio, output RPM, torque, and mechanical advantage.

1cr · v2026-04-22

Physics

Angular Velocity Calculatorangular-velocity-calculator

Convert angular velocity between rad/s, RPM, Hz, deg/s, and period, or derive it from linear speed and radius with tangential and centripetal results.

1cr · v2026-04-22

Density Calculatordensity-calculator

Solve density, mass, or volume with common unit conversions.

1cr · v2026-04-22

Doppler Effect Calculatordoppler-effect-calculator

Observed frequency shift for moving sources and observers, classical for sound or relativistic for light.

1cr · v2026-04-22

Falling Through Earth Calculatorfalling-through-earth-calculator

Calculate idealized uniform-density gravity-train travel time and speed.

1cr · v2026-04-22

Force Calculatorforce-calculator

Solve Newton's second law for force, mass, or acceleration with common unit conversions.

1cr · v2026-04-22

Heat Transfer Calculatorheat-transfer-calculator

Calculate heat transfer by conduction, convection, or radiation.

1cr · v2026-04-22

Kinetic Energy Calculatorkinetic-energy-calculator

Solve kinetic energy, mass, or velocity with KE = 1/2 m v^2 and unit conversions.

1cr · v2026-04-22

Lens Equation Calculatorlens-equation-calculator

Thin-lens equation solver for image distance, focal length, or object distance with magnification and image properties.

1cr · v2026-04-22

Moment of Inertia Calculatormoment-of-inertia-calculator

Area moment of inertia (rectangle, circle, hollow circle, triangle) or mass moment of inertia (rod, cylinder, sphere, hollow cylinder), in SI units.

1cr · v2026-04-22

Momentum Calculatormomentum-calculator

Calculate linear momentum and kinetic energy from mass and velocity.

1cr · v2026-04-22

Pendulum Period Calculatorpendulum-period-calculator

Simple pendulum solver for period, length, gravity, or frequency with planet presets and a large-amplitude correction.

1cr · v2026-04-22

Potential Energy Calculatorpotential-energy-calculator

Calculate gravitational or elastic potential energy and solve for missing variables.

1cr · v2026-04-22

Projectile Motion Calculatorprojectile-motion-calculator

Projectile range, max height, flight time, and impact speed/angle from launch speed, angle, height, and gravity.

1cr · v2026-04-22

Snell's Law Calculatorsnell-s-law-calculator

Refraction angles, indices, critical angle, and Brewster angle from Snell's law with a built-in material library.

1cr · v2026-04-22

Specific Heat Capacity Calculatorspecific-heat-capacity-calculator

Solve Q = m*c*dT for heat, mass, specific heat, or final temperature with a substance library and mixed units.

1cr · v2026-04-22

Spring Constant Calculatorspring-constant-calculator

Hooke's law solver for force, spring constant, or displacement, plus elastic energy and oscillation period.

1cr · v2026-04-22

Stopping Distance Calculatorstopping-distance-calculator

Vehicle reaction + braking stopping distance by road condition (dry/wet/snow/ice), km/h or mph.

1cr · v2026-04-22

Terminal Velocity Calculatorterminal-velocity-calculator

Terminal velocity from mass, drag coefficient, area, and fluid density, with object presets and approach-time milestones.

1cr · v2026-04-22

Thermal Expansion Calculatorthermal-expansion-calculator

Calculate linear, area, or volume thermal expansion for common materials.

1cr · v2026-04-22

Torque Calculatortorque-calculator

Solve torque, force, lever arm distance, or angle using tau = F r sin(theta).

1cr · v2026-04-22

Velocity Calculatorvelocity-calculator

Calculate average velocity, distance, time, or relative velocity with distance, time, and speed units.

1cr · v2026-04-22

Work and Power Calculatorwork-and-power-calculator

Calculate mechanical work and power with common unit conversions.

1cr · v2026-04-22

Work Calculatorwork-calculator

Calculate mechanical work from force, distance, and angle.

1cr · v2026-04-22

Physics Calculators

Buoyancy Calculatorbuoyancy-calculator

Calculate buoyant force, object density, apparent weight, and float/sink verdict.

1cr · v2026-04-22

Coulomb's Law Calculatorcoulomb-s-law-calculator

Electrostatic force between two point charges via Coulomb's law, solving for force, charge, or distance with dielectric media.

1cr · v2026-04-22

de Broglie Wavelength Calculatorde-broglie-wavelength-calculator

Calculate a particle's de Broglie wavelength from velocity or kinetic energy.

1cr · v2026-04-22

E=mc² Calculatore-mc-calculator

Convert mass and energy using E=mc² with configurable conversion efficiency.

1cr · v2026-04-22

Electricity Calculatorelectricity-calculator

Solve voltage, current, resistance, and power from any two known Ohm's law values.

1cr · v2026-04-22

Escape Velocity Calculatorescape-velocity-calculator

Calculate escape velocity for preset or custom celestial bodies.

1cr · v2026-04-22

Gravitational Force Calculatorgravitational-force-calculator

Solve Newton's universal gravitation equation for force, mass, or distance.

1cr · v2026-04-22

Ideal Gas Law Calculatorideal-gas-law-calculator

Solve PV=nRT for pressure, volume, moles, or temperature with unit conversion.

1cr · v2026-04-22

Kepler's Third Law Calculatorkepler-s-third-law-calculator

Calculate orbital period and mean velocity from semi-major axis and central mass.

1cr · v2026-04-22

Photon Energy Calculatorphoton-energy-calculator

Convert photon wavelength, frequency, and energy using E=hf=hc/lambda.

1cr · v2026-04-22

Time Dilation Calculatortime-dilation-calculator

Relativistic time dilation, Lorentz factor, clock rate, and optional length contraction at any sub-light speed.

1cr · v2026-04-22

Pressure

Bar to PSI Converterbar-to-psi-converter

Convert bar and PSI, including kPa, MPa, atm, torr, inHg, and Pa.

1cr · v2026-04-22

psi to kPa Converterpsi-to-kpa-converter

Convert pounds per square inch to kilopascals and related pressure units.

1cr · v2026-04-22

Temperature

Celsius to Fahrenheit Calculatorcelsius-to-fahrenheit-calculator

Convert Celsius to Fahrenheit and related temperature scales.

1cr · v2026-04-22

Celsius to Kelvin Convertercelsius-to-kelvin-converter

Convert Celsius to Kelvin and related temperature scales.

1cr · v2026-04-22

Celsius to Rankine Convertercelsius-to-rankine-converter

Convert Celsius to Rankine and related temperature scales.

1cr · v2026-04-22

Fahrenheit to Celsius Calculatorfahrenheit-to-celsius-calculator

Convert Fahrenheit to Celsius and related temperature scales.

1cr · v2026-04-22

Fahrenheit to Kelvin Converterfahrenheit-to-kelvin-converter

Convert Fahrenheit to Kelvin and related temperature scales.

1cr · v2026-04-22

Fahrenheit to Rankine Converterfahrenheit-to-rankine-converter

Convert Fahrenheit to Rankine and related temperature scales.

1cr · v2026-04-22

Kelvin to Celsius Converterkelvin-to-celsius-converter

Convert Kelvin to Celsius and related temperature scales.

1cr · v2026-04-22

Kelvin to Fahrenheit Converterkelvin-to-fahrenheit-converter

Convert Kelvin to Fahrenheit and related temperature scales.

1cr · v2026-04-22

Rankine to Celsius Converterrankine-to-celsius-converter

Convert Rankine to Celsius and related temperature scales.

1cr · v2026-04-22

Rankine to Fahrenheit Converterrankine-to-fahrenheit-converter

Convert Rankine to Fahrenheit and related temperature scales.

1cr · v2026-04-22

Unit Converters

Energy Converterenergy-converter

Convert energy between joules, calories, BTU, watt-hours, electronvolts, ergs, and therms.

1cr · v2026-04-22

Power Converterpower-converter

Convert power among watts, kilowatts, horsepower, BTU per hour, refrigeration tons, and related units.

1cr · v2026-04-22

Ultimate Frequency & Wavelength Converterultimate-frequency-wavelength-converter

Convert between frequency and wavelength using a configurable propagation speed and identify the spectrum band.

1cr · v2026-04-22

Weather

Dew Point Calculatordew-point-calculator

Calculate dew point temperature from air temperature and relative humidity using the Magnus formula.

1cr · v2026-04-22

Heat Index Calculatorheat-index-calculator

Calculate the NWS heat index (apparent temperature) from air temperature and relative humidity.

1cr · v2026-04-22

Wind Chill Calculatorwind-chill-calculator

Calculate NWS wind chill and frostbite risk from air temperature and wind speed.

1cr · v2026-04-22