About capacity:
250GB = aproximadamente 200GB-240GB
256GB=approximately 210GB-245GB
500GB=approximately 440GB-490GB
512GB=approximately 450GB-500GB
1TB=approximately 880GB-980GB
2TB=approximately 1760GB-1960GB
4TB=approximately 3520GB-3920GB
8TB=approximately 7060GB-7840GB
1MB=1000KB. This is calculation difference between manufacturer(1GB=1000MB) and our PC(1GB=1024MB), please Google Memory card capacity to get more information