How much is one MB?

Originally it’s 1024 kB, each kB is 1024B. This makes a total of 1024³ bytes (1073741824).

Using 1024 instead of 1000 has its roots in the fact that computers usually work with blocks of 1024 bytes (2¹⁰).

Other people stick to the SI and deem one MB 1000³ bytes (1000000000).

To get rid of confusion binary multiples were introduced. One MiB = 1024³, where one MB would be 1000³.

When buying something one should take notice of this, because the difference between one GB and one GiB is 74MB (or 70 MiB).

With ever increasing storage capability there would be a time where one VendekaByte would be half of one VendebiByte. (Vendika = 10³⁰)