What is a Data Size Converter?
Storage marketing uses decimal units (1 GB = 10⁹ bytes) while operating systems often report binary ones (1 GiB = 2³⁰ bytes): which is exactly why a “1 TB” drive shows as 931 GB.
Enter a value in any unit and see it in every unit of both systems simultaneously.
The gap widens one step at a time: a KiB is 2.4% larger than a KB, a MiB 4.9%, a GiB 7.4% and a TiB a full 10%. That compounding is why a 500 GB SSD reports 465.7 GB and a 4 TB drive reports 3.64 TB, while on a 200 KB file it is invisible. Network speeds and storage sales are both decimal, so the drive is where most people first meet it.
Frequently asked questions
Should I write MB or MiB in a spec?
Write MiB when you mean 1,048,576 bytes and MB when you mean a million, then state which you used in the first line anyway. The IEC binary prefixes have been standardised since the late 1990s and are still widely ignored, so naming the unit beats assuming the reader shares your convention.
Is RAM measured in decimal or binary units?
Binary, always: a 16 GB memory module is 16 GiB, or 17.18 billion bytes, because memory is addressed in powers of two. Storage is sold in decimal and network speeds are decimal, which is why the drive is the component that looks short and the RAM never does.
Why does my 1 TB drive show 931 GB?
The drive holds 10¹² bytes; your OS divides by 2⁴⁰ and calls it GiB (labeled GB). Both are “right”: the units differ.
KB vs KiB?
KB = 1000 bytes (decimal, SI); KiB = 1024 bytes (binary). The i marks the binary unit.
Which convention should I use?
Networking and storage sales: decimal. Memory and many OS displays: binary. When precision matters, write the unit explicitly.
How large can values be?
Anything sensible: very large or small values switch to scientific notation for exactness.