Adventure Era:
In the adventure era Sonic in his Super Form was able to defeat Perfect Chaos who is powered by all the 7 Chaos Emeralds
A Single Chaos Emerald is able to break the world into seven parts
Multi Continental to Large PlanetSo it would be no exaggeration to say that Perfect Chaos would be Large Planet level since the main reason to why Chaos lost it's because of his inability to harness the positive energy of the Chaos Emeralds
Later in Sonic Generations, Sonic once again managed to defeat Perfect Chaos, but this time in his base form, that's due to the constant Progression in power that Sonic had making Generations base Sonic> SA1 Super Sonic =Large Planet level
In Sonic lost world Sonic, Managed to defeat the Egg Robo a giant mech powered by the life energy of Sonic's world who has been calculated to be Dwarf Star level
Egg Robo (Lost World) is Dwarf Star level.