We know that Goku in DB had a power level of 10 by the Pilaf saga, and it was around there that he used the Kamehameha and busted up a whole car (albeit a tiny one).
We also know that the Crazy Wizards from AA (that’s what I’m using as the lowest of the low in power levels here) couldn’t break the rubble around them (correct if wrong), making them weaker than Goku at the time.
Then again, earthlings have the ability to spike their power levels while using a technique, so maybe Goku’s Kamehameha didn’t have a power level of 10. In the Raditz Saga, Goku had a base power level of 416 but his kamehameha had one of 924. That’s more than twice his base power. I don’t know what power level that Kamehameha he used on the car, but it’s safe to assume somewhere around 20 ~ 30.
AA Wizards don’t have this ability afaik, so at the very least, they have a power level of less than 20 but probably more than Adult Bulma in Namek Saga (who had one of 12). So maybe 25.
So that’s a start. What do y’all think Theos’ power level is, for instance?