Measured diagonally, Galaxy S21 5G’s screen size is 6.2″ in the full rectangle and 6.1″ with accounting for the rounded corners, Galaxy S21+ 5G’s screen size is 6.7″ in the full rectangle and 6.5″ with accounting for the rounded corners and Galaxy S21 Ultra 5G’s screen size is 6.8″ in the full rectangle and 6.6″ with accounting for the rounded corners; actual viewable area is less due to the …

https://www.samsung.com/us/smartphones/galaxy-s21-ultra-5g/models/