When constructing terrestrial planets, a worldbuilder needs to work with three important variables: mass, radius and density.
Set those values correctly and the result with be a small rocky planet. Set them incorrectly and a terrestrial planet can come out looking more like Neptune than Earth. Or worse still, the planet will be utterly implausible.
Want to make sure your terrestrial planet is both rocky and plausible?
As always, Artifexian has you covered. Check out the video below.