🪐 Modern Physics & Astronomy Calculators
Relativity, quantum physics, nuclear decay, orbits and stars. Browse 69 free modern physics & astronomy calculators, each with the formula, a worked example and an interactive chart.
E = mc² Mass-Energy CalculatorConvert mass to energy using Einstein's equation.Time Dilation CalculatorFind how time slows for a fast-moving observer.Length Contraction CalculatorFind how length shrinks at relativistic speeds.Relativistic Kinetic Energy CalculatorCompute relativistic kinetic energy and momentum.Relativistic Velocity Addition CalculatorAdd two velocities using special relativity.Photoelectric Effect CalculatorFind maximum electron kinetic energy and stopping voltage.de Broglie Wavelength CalculatorFind the matter wavelength of a moving particle.Heisenberg Uncertainty CalculatorFind the minimum momentum or velocity uncertainty for a given position uncertainty.Hydrogen Atom Energy Levels (Bohr Model) CalculatorFind hydrogen energy level and transition photon.Particle in a Box Energy CalculatorFind quantized energy levels for a particle in a 1D box.Radioactive Decay CalculatorFind the amount remaining after radioactive decay.Half-Life from Measurements CalculatorFind half-life from two measurements of a decaying sample.Carbon-14 Dating CalculatorEstimate the age of a sample from its remaining carbon-14.Radioactivity Activity CalculatorFind activity of a radioactive sample from atoms and half-life.Radiation Dose CalculatorConvert absorbed dose to equivalent dose in sieverts.Nuclear Binding Energy CalculatorFind binding energy from the mass defect.Fusion Energy Release CalculatorCompute energy released from a mass loss in fusion reactions.Orbital Velocity CalculatorFind the orbital speed and period of a satellite.Escape Velocity CalculatorFind the speed needed to escape a planet's gravity.Kepler's Third Law CalculatorFind orbital period from the semi-major axis around the Sun.Schwarzschild Radius (Black Hole) CalculatorFind the event horizon radius of a black hole.Surface Gravity of a Planet CalculatorCompute gravity at a planet's surface from mass and radius.Light Travel Time CalculatorFind how long light takes to travel a distance.Light-Year ConverterConvert light-years to kilometres, AU and parsecs.Stellar Parallax Distance CalculatorFind the distance to a star from its parallax angle.Stellar Luminosity CalculatorEstimate a star's luminosity from radius and temperature.Distance Modulus (Star Magnitude) CalculatorFind absolute magnitude from apparent magnitude and distance.Hubble's Law CalculatorEstimate recession speed of a galaxy from its distance.Redshift CalculatorCompute redshift from observed and emitted wavelength.Tidal Force CalculatorEstimate the tidal acceleration across a body from a nearby mass.Synodic Period CalculatorFind the time between planetary alignments.Tsiolkovsky Rocket Equation CalculatorFind the delta-v of a rocket from its mass ratio.Hill Sphere Radius CalculatorEstimate the region where a planet's gravity dominates.Compton Scattering Wavelength Shift CalculatorFind how much an X-ray or gamma photon lengthens in wavelength when it scatters off an electron.Electron Wavelength from Accelerating Voltage CalculatorFind the de Broglie wavelength of an electron accelerated through a given voltage, as used in electron microscopes.X-ray Tube Cutoff Wavelength CalculatorFind the shortest wavelength of X-rays produced by an X-ray tube at a given voltage.Pair Production Threshold CalculatorFind the energy a gamma photon needs to create an electron and positron pair, and the energy left over.Nuclear Reaction Q-Value CalculatorFind the energy released or absorbed in a nuclear reaction from the atomic masses of reactants and products.Photon Momentum CalculatorFind the momentum carried by a single photon from its wavelength.Lorentz Factor and Relativistic Energy CalculatorFind the Lorentz factor and kinetic energy of an object moving at a large fraction of light speed.Twin Paradox Ageing CalculatorFind how much less a travelling twin ages on a round trip at high speed.Relativistic Doppler Shift CalculatorFind the observed wavelength of light from a fast-moving source moving towards or away from you.Decay Constant and Mean Lifetime CalculatorFind the decay constant and mean lifetime of a radioactive isotope from its half-life.Radiation Shielding Half-Value Layer CalculatorFind how much radiation a shield blocks and the thickness that halves it.Radiation Dose Rate vs Distance CalculatorEstimate the radiation dose rate at a new distance from a point source using the inverse-square law.Nuclear Radius Estimate CalculatorEstimate the radius and volume of an atomic nucleus from its mass number.Bohr Orbit Radius CalculatorFind the radius of an electron orbit in a hydrogen-like atom.Quantum Tunnelling Probability CalculatorEstimate the chance an electron tunnels through a barrier taller than its energy.Gravitational Redshift CalculatorFind how much light from the surface of a massive body is shifted to longer wavelengths by gravity.Hubble Time CalculatorEstimate the age scale of the universe from the Hubble constant.Critical Density of the Universe CalculatorFind the critical density of the universe from the Hubble constant and its equivalent in hydrogen atoms.Main Sequence Star Lifetime CalculatorEstimate how long a star stays on the main sequence from its mass.Geostationary Orbit Height CalculatorFind the radius and altitude of an orbit that keeps a satellite fixed over one point on Earth.Binary Star Total Mass CalculatorFind the total mass of a binary star system from its orbit size and period.Distance from Magnitudes CalculatorFind the distance to a star from its apparent and absolute magnitudes.Stellar Radius from Luminosity CalculatorFind the radius of a star from its luminosity and surface temperature.Particle Lifetime from Decay Width CalculatorFind the mean lifetime of an unstable particle from its decay width.Mass to Energy and TNT Equivalent CalculatorFind the energy released if a given mass is converted completely into energy, and its TNT equivalent.NMR Larmor Frequency CalculatorFind the resonance frequency of hydrogen nuclei in a magnetic field, as used in MRI and NMR.Thermal Neutron Speed CalculatorFind the typical speed of neutrons in thermal equilibrium at a given temperature.Uranium Fission Energy CalculatorEstimate the energy released by fissioning a mass of uranium-235 at about 200 MeV per fission.Radiation Pressure Force CalculatorFind the pressure and force that light exerts on a perfectly absorbing surface.Gravitational Clock Offset CalculatorEstimate how much faster a clock runs at a higher altitude because of weaker gravity.Muon Survival Fraction CalculatorFind the fraction of fast muons that survive to reach the ground, using time dilation.Atomic Mass Unit ConverterConvert a mass in atomic mass units into energy in MeV and mass in kilograms.Electronvolt to Wavelength ConverterConvert a photon energy in electronvolts into wavelength and frequency.Compton Edge Energy CalculatorFind the maximum energy an electron can gain when a gamma ray scatters from it, as seen in gamma spectra.Charged Particle Bending Radius CalculatorFind the radius of the circular path of a fast charged particle in a magnetic field.Blackbody Radiation Energy Density CalculatorFind the energy density of thermal radiation at a given temperature, such as the cosmic microwave background.
About Modern Physics & Astronomy calculators
Relativity, quantum physics, nuclear decay, orbits and stars. CalcDepo has 69 free modern physics & astronomy calculators. Each one shows the formula, the variables and their units, a worked example and a chart of how the result changes, so you can check homework, plan a lab or understand the idea behind the numbers.
Popular calculators here include E = mc² Mass-Energy, Time Dilation, Length Contraction, Relativistic Kinetic Energy, Relativistic Velocity Addition, Photoelectric Effect. Common searches in this category include “how much energy in a gram”, “twin paradox”, “spaceship length”, “energy at high speed”.
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