Do you want to know how much power output you will need to power up your LED strips?
Measure the length of the LED/COB/SMD 835 strip that you will be using in feet
Get the wattage per foot rating of your low voltage LED/COB/SMD 2835 strip (example 2.6w/ft)
Once you have the length and wattage per foot, click the "Calculate" in the calculator
The Calculator will then Display the recommended upper and lower limit amount of Power you'll need for your installation
Note - The calculator will not exactly tell you the power supply or driver that you will use but it will let you know how much is the recommended lower limit or upper limit of the transformer you need.