Just wondering really.
Somewhere between Odin and Galactus, if it's an average Celestial.
I would put them at least on par with a fully fed Galactus...
When the Skyfathers of Earth's dimension: Odin, Zeus, and Vishnu combined their energies into a single attack powerful enough to reduce an entire galaxy to nothingness and attacked the Celestial leader known as Arishem the Judge, the combined might of the Skyfathers failed to even faze Arishem in the slightest. Arishem the Judge responded by threatening to permanently seal off the dimensional links to Asgard, Olympus, and Nirvana along with the rest of the realms belonging to other Godheads, which frightened the Skyfathers to the point that they went down on their knees and acknowledged their inferiority to the all-powerful Celestial leader.