Tips:
The actual usage capacity of the 32GB memory card is about 29.1GB, because the computer uses binary system and the manufacturer uses decimal system when producing it.

The computer is 1MB=1024KB, the manufacturer is 1MB=1000KB

So after calculation, 2GB is about 1.85GB, 4GB is about 3.7GB, 8GB is about 7.3GB, 16GB is about 14.6GB, 32GB is about 29.11GB.