Astronomy Calculators

Orbital Speed

Velocity around a central body.

Orbital Period

Time for one revolution.

Escape Velocity

Speed to escape gravity.

Gravitational Force

Newton’s universal law.

Celestial Mass

From orbital data.

Distance Modulus

From magnitude difference.

Luminosity

Star’s total energy output.

Stellar Radius

From L and T.

Blackbody Radiation

Planck’s spectral intensity.

Redshift

Cosmological expansion.

Parallax Distance

From angular shift.

Apparent Magnitude

Brightness from Earth.

Absolute Magnitude

Intrinsic brightness.

Planetary Density

Mass / volume.

Surface Gravity

On planet surface.

Telescope Magnification

Focal length ratio.

Radiant Energy

Flux × time.

Stellar Temperature

Wien’s law.

Space Distance

AU, ly, pc converter.

Satellite Altitude

From orbital period.

Kepler's 3rd Law

T² ∝ a³ solver.

Hubble Constant

v = H₀ × d.

Event Horizon

Schwarzschild radius.

Synodic Period

Earth-planet alignment.

Light Travel Time

Distance / c.

Angular Diameter

Size / distance.

Field of View

Telescope or camera.

Exoplanet Transit

Depth, duration, period.

Roche Limit

Tidal disruption distance.

Hill Sphere

Gravitational dominance.