🔭 Astronomy & Space Calculators
Explore the solar system and the universe: orbital mechanics, stellar magnitudes, cosmological distances, calendars and lunar phases. Constants follow IAU and CODATA values.
No tools match your search.
- Weight on Other Planets CalculatorHow much would you weigh on the Moon, Mars, Jupiter and other planets? Compare your weight across the solar system.
- Escape & Orbital Velocity CalculatorEscape velocity, circular orbital velocity, surface gravity and orbital period for planets or any custom body.
- Kepler's Third Law CalculatorOrbital period from semi-major axis (or vice-versa) for any central mass, with solar-system shortcuts.
- Julian Date ConverterConvert a calendar date and time (UTC) to Julian Date, Modified Julian Date and day of year.
- Moon Phase CalculatorMoon phase, illumination and age for any date, plus the next new and full moon.
- Apparent & Absolute MagnitudeConvert between apparent magnitude, absolute magnitude and distance using the distance modulus.
- Hubble's Law & Redshift CalculatorRecession velocity and approximate distance of a galaxy from its redshift (low-z Hubble law).
- Schwarzschild RadiusEvent horizon radius, surface gravity and Hawking temperature of a non-rotating black hole.
- Star Luminosity CalculatorLuminosity, absolute bolometric magnitude and peak wavelength of a star from radius and temperature.
- Angular Size CalculatorAngular diameter of an object from its size and distance, or size from angle and distance.
- Light Travel Time CalculatorHow long light (or a radio signal) takes to travel a given distance, e.g. Earth to Mars.