Astronomy Calculators
Free online astronomy calculators for orbital velocity, telescopes, light-years, stellar magnitude, and more.
Delta-V Budget Calculator
Calculate fuel mass and mass ratio for any rocket mission using the Tsiolkovsky rocket equation. Enter delta-v, exhaust velocity, and dry mass to find total fuel required.
Newtonian Telescope Collimation Calculator
Calculate the secondary mirror offset for a Newtonian reflector telescope to achieve correct collimation. Ensure accurate optical alignment for sharp views.
Orbital Velocity Calculator
Calculate the orbital velocity needed for a satellite or object to orbit a planet or star at a given altitude.
Star Magnitude Calculator
Calculate the brightness ratio between stars using apparent magnitude. Compare stellar magnitudes.
Telescope Field of View Calculator
Calculate the true and apparent field of view for your telescope and eyepiece combination.
Telescope Limiting Magnitude Calculator
Calculate the faintest star your telescope can see based on aperture size. Compare visual limits across telescope types.
Telescope Magnification Calculator
Calculate telescope magnification, field of view, and exit pupil from focal lengths. Find the best eyepiece for your telescope.
Light Year Distance Calculator
Convert between light years, kilometers, miles, and astronomical units (AU). Works in both directions.
Weight on Other Planets Calculator
Enter your Earth weight to see what you would weigh on every planet in the solar system, plus the Moon and Sun.