Astronomy

Astronomy Calculators

Moon phases, planetary weight, telescopes, orbits, magnitudes, and distances.

Find a tool in Astronomy

8 tools

Distance Modulus Calculator

Distance modulus calculator: distance from apparent and absolute magnitude.

Light year distance calculator: convert light years to kilometers, miles, and AU.

Moon phase calculator: current moon phase from the synodic cycle.

Orbital period calculator: circular orbit period around Earth from altitude (Kepler).

Planetary weight calculator: your weight on other planets and moons from surface gravity ratios.

Star magnitude calculator: brightness ratio between two apparent magnitudes.

Stellar temperature calculator: blackbody temperature from peak wavelength (Wien's law).

Telescope magnification calculator: power from focal length and eyepiece.