2D Sprite Resolution issue

looking to find the right method (for my 4" smart phone up to 6" infinity display) , to create sprites and the right resolution I should generate it. I use Inkscape to create vector images and generate to raster, but what will be the right resolution to generate for such mobile devices and how can I implement in unity.

Post Sprites creation, I intend to use Pixel Per Unit over Scaling the sprites.

My game is 2D Arcade game and solely for iOS and Android.

just test it. try one, and build to your phone. if that’s fine, stick to that