Hello, your final bra size will depend on the type of bra you purchase, your own breast size and shape, and the implants. This is why there is no direct correlation between implant size and final cup size. I would recommend seeing a board-certified PS to help you choose implants.
A specific size of breast implants won't be able do give a D cup or any specific cap to all the people. The bra cup size is a relation of the breast to the chest cage of the patient. Therefore women with a the same implant size and different chest cage will give different size cupsThe best way to determine if an specific breast implant will give XYZ cup size is do to a breast implant fitting exercise during a consultation with a boar certified plastic surgeon.