Data Storage Converter

Storage manufacturers label drives using SI (decimal) prefixes where 1 GB = 1,000,000,000 bytes (10⁹), following standard metric conventions used throughout science and engineering. Operating systems, however, historically count in binary where 1 GiB (gibibyte) = 1,073,741,824 bytes (2³⁰), because computer memory is addressed in powers of two. This discrepancy means a drive advertised as 1 TB shows roughly 931 GiB in Windows Explorer or macOS Finder — the drive capacity is correct, the OS is just measuring in base-2 units while the marketing used base-10.

Neither side is wrong; they simply use different base systems. The IEC introduced binary prefixes (KiB, MiB, GiB, TiB) in 1999 specifically to eliminate this ambiguity, but adoption has been inconsistent. macOS and Windows both report binary sizes but label them with decimal prefixes (so macOS says "931 GB" when it technically means 931 GiB). Linux distributions are more careful, with most modern file managers explicitly labeling binary units. Network speeds, RAM capacity, and flash drive advertising are other common areas where the binary-decimal confusion costs consumers perceived capacity.

The gap between decimal and binary sizing widens with larger drives: a 4 TB drive appears as about 3.63 TiB (a 9.3% apparent reduction), an 8 TB drive shows as 7.28 TiB, and a 16 TB drive shows as 14.55 TiB. When planning storage for backups, media servers, or database allocations, always budget using the binary figure your OS reports rather than the manufacturer's advertised capacity — allocating "1 TB for backups" produces problems if you bought what the manufacturer calls a 1 TB drive and your backup system assumes 1 TiB of usable space.

For network speeds, remember that ISPs and network equipment quote bandwidth in megabits per second (Mbps), while file download progress bars display megabytes per second (MB/s). Divide Mbps by 8 to get MB/s — a 100 Mbps connection maxes out at 12.5 MB/s of file transfer throughput. This is the source of frequent consumer confusion: a "gigabit internet" plan delivers 1,000 Mbps, or about 125 MB/s of maximum theoretical file transfer. Real-world speeds run 80–95% of rated maximum due to protocol overhead (TCP/IP headers, retransmission, encryption). Storage device speeds (SSD read/write, HDD throughput) are typically quoted in MB/s directly, so no conversion needed when matching storage throughput to network throughput.

The calculator converts between bits, bytes, and all standard multiples in both SI (decimal, powers of 10) and IEC (binary, powers of 2) systems. The fundamental relationship is 1 byte = 8 bits (the byte is the basic addressable unit in most computer architectures, while the bit is the smallest data unit). Higher units follow the chosen system: 1 KB = 1,000 bytes (decimal), 1 KiB = 1,024 bytes (binary); 1 MB = 1,000,000 bytes, 1 MiB = 1,048,576 bytes; and so on up through PB/PiB and EB/EiB for enterprise-scale storage.

Small changes in input produce proportional changes in output, which makes the converter useful for double-checking vendor quotes, storage allocation plans, and network bandwidth calculations. When comparing storage products or reading technical documentation, always check whether the source uses decimal or binary units — a 1 TB SSD and a 1 TiB SSD are not the same product (the 1 TiB unit would contain about 10% more actual bytes). For precise work involving large files or enterprise storage, always specify units explicitly (GB vs GiB) to avoid the chronic ambiguity that comes from casual usage of "gig" or "meg" without specifying the underlying counting system.