The capacity of USB flash drives can vary widely, with common capacities ranging from a few gigabytes to several terabytes. Some common storage capacities for USB flash drives include:

4 GB
8 GB
16 GB
32 GB
64 GB
128 GB
256 GB
512 GB
1TB (terabyte)
2TB (terabyte)
Note that not all USB flash drive models will be available in every capacity, and larger capacities may be more expensive. It’s important to choose a capacity that meets your needs while staying within your budget.