[hgoel]

Don't these estimates assume launching from the surface, fully via rocket? On Earth, having air breathing stages to gradually build up speed, or using other launch mechanisms, isn't worthwhile because rockets are more cost effective here, but those tradeoffs change if you're on a planet with higher gravity and a denser atmosphere.

[dogma1138]

You still need to get to escape velocity that doesn’t change the delta v required does but not by that much you are looking at 5-10%. Maybe a bit more if the atmosphere is really really thick.

Unless you skip chemical rockets altogether there is a pretty hard cap on how much bigger a planet can be than earth before a space capable civilization becomes almost impossible.