Astronomy & Space Calculators
Your weight and age across the planets, escape velocity, orbits, light-years, rockets, and black holes.
13 calculators
- Weight on Other Planets CalculatorFind out how much you would weigh on the Moon, Mars, Jupiter, and every other body in the solar system — your weight scaled by each world's gravity.
- Age on Other Planets CalculatorSee how old you are on Mercury, Mars, Jupiter, and every planet — one planetary year is one orbit of the Sun, and each world takes a different time.
- Escape Velocity CalculatorCalculate the escape velocity of any planet, moon, or star from its mass and radius — the speed needed to leave its gravity behind forever.
- Orbital Period CalculatorCalculate the orbital period and speed of a satellite or planet with Kepler's third law, from the orbit's size and the mass it goes around.
- Light Travel Time & Distance CalculatorConvert any distance into how long light takes to cross it, and light-years into kilometres — the natural way to measure the scale of space.
- Rocket Equation CalculatorWork out a rocket's delta-v from its specific impulse and mass ratio using the Tsiolkovsky equation — and see why spacecraft are mostly fuel.
- Black Hole CalculatorEnter a mass and find a black hole's event horizon (Schwarzschild radius), its Hawking temperature, and how long it would take to evaporate.
- Star Luminosity CalculatorCalculate a star's total luminosity from its radius and surface temperature using the Stefan–Boltzmann law, in watts and multiples of the Sun.
- Telescope Magnification CalculatorCalculate telescope magnification from the focal lengths, plus exit pupil, true field of view, and the minimum and maximum useful magnification for your aperture.
- Moon Phase CalculatorFind the Moon's phase on any date — its age in days, the illuminated fraction, and the dates of the next new and full moons — from the mean lunar cycle.
- Parallax Distance CalculatorConvert a star's parallax angle into its distance in parsecs, light-years, and astronomical units — the geometric method that anchors the cosmic distance ladder.
- Angular Size CalculatorCalculate the angular size (apparent size) of an object from its actual diameter and distance, in degrees, arcminutes, and arcseconds.
- Redshift CalculatorCalculate cosmological redshift z from observed and rest wavelengths, the recession velocity (classical and relativistic), and a Hubble-law distance estimate.