The mechanical specifications for the package shows the dimensions.

WLCSP package

Figure 1. WLCSP 1.9x1.9 mm package
WLCSP package (placeholder)
Table 1. WLCSP dimensions in millimeters
A A1 A2 A3 A5 D E D2, E2 F, G e b
Min. 0.406 0.14 0.244 0.022 0.19
Typ. 0.464 0.269 0.03 0.025 1.9175 1.8975 1.32 0.66 0.44
Max. 0.522 0.2 0.294 0.028 0.25

QFN package

Figure 2. QFN16 4.0x4.0 mm package
QFN package
Table 2. QFN dimensions in millimeters
A A1 A2 A3 A4 D, E D2, E2 L K e b
Min. 0.8 0 3.9 2.55 0.35 0.25
Typ. 0.85 0.035 0.65 0.08 0.203 4.0 2.65 0.4 0.275 0.65 0.3
Max. 0.9 0.05 0.67 4.1 2.75 0.45 0.35