16 GB = Approx. 14 ~ 14.6GB
32 GB = Approx. 28 ~ 30 GB
64 GB = Approx. 58 ~ 60 GB
128 GB = Approx. 115 ~ 118 GB
200 GB = Approx. 180 ~ 186 GB
256 GB = Approx. 230 ~ 236 GB
This is calculation difference between manufacturer and your PC, please Google 'Memory card capacity' to get more information. Your PC says 1GB = 1.073741824 Billion bytes where Market Defines 1 GB = 1.00 Billion bytes.The pursuit of the perfect person is not recommended to buy.
Steps to verify the Capacity and Speed of the memory card
(1). Please use quality USB 3.0 card reader to verify all memory card by H2testw on PC. Real
memory card should pass H2testw with no error.
(2). Please don't use cheap card reader to test Micro SD card, speed of Micro SD card will be reduced by low quality card reader.
(3). Micro SD memory card speed is greatly affected by card reader and the capacity you choose , USB port etc. Low quality device will 100% slow down card speed,1MB=1000KB.