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:

4GB
8GB
16GB
32GB
64GB
128GB
256GB
512GB
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.