Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Angular Size Calculator

Calculate how large a celestial object appears in the sky given its physical diameter and distance. Perfect for comparing the apparent sizes of planets, moons, nebulae, and galaxies.

Physical Diameter (km)

Distance (km)

Fill in the required fields to see your result.

Astronomy

Roche Limit Calculator

Find the critical orbital distance inside which a satellite is torn apart by tidal forces. Use it to understand ring formation, comet disruption, and satellite stability around planets.

Primary Radius (km)

Primary Density (kg/m³)

Satellite Density (kg/m³)

Fill in the required fields to see your result.

Key differences

	Angular Size Calculator	Roche Limit Calculator
Category	Astronomy	Astronomy
Inputs required	2	3
Result	Angular Size (arcsec)	Roche Limit (km)
What it does	Calculate how large a celestial object appears in the sky given its physical diameter and distance. Perfect for comparing the apparent sizes of planets, moons, nebulae, and galaxies.	Find the critical orbital distance inside which a satellite is torn apart by tidal forces. Use it to understand ring formation, comet disruption, and satellite stability around planets.