In NJ, property taxes are not calculated based on sales price (excluding new construction), but on the township's assessed value of your home. If you are inquiring as to the equation the township uses to calculate your property taxes, you can all Medford Lakes Township Office at, (609) 654-8898. However, Medford Lakes will be reassessing property values within the next few years and the equation they currently use may change. You can find out the current assessed value of your home by looking at a copy of your most recent tax record.
Remember, there are essentially three values assigned to your home - Current Market Value, Townhip Assessed Value, and Appraised Value. In an ideal world, all three values would be equal, but is usually not the case.
I hope this answered your question! If you have any additional questions or need further clarification, please feel free to call or e-mail me at any time.