How is assessed value calculated in Philadelphia?

[Cliff T.]

Anyone know of a good way to estimate how assessed value for a property in Philadelphia will change after purchase? For example, if the current assessed value for a property is $800,000 and I plan to purchase at $1,000,000. Will the assessed value jump to $1mm, based on the sale? Or will it land somewhere in between?

I've looked on the Philadelphia tax assessor's website and came up short on details. I also know the city has recently been under scrutiny for having issues with their property assessed values, but it surprised me that their formula for calculating the value is not a bit more transparent.

Any help would be much appreciated. Thanks in advance!