Data Storage & Speed Converter
Storage capacity (bytes, KB, MB, GB, TB) and transfer speed (Mbps, MB/s) are related but different things — convert either one below, and see how they connect.
Storage capacity
How much data something holds — a file, a drive, a memory cardCommon conversions
Storage reference
What 1 gigabyte equals in every other unit.
| Unit | Value |
|---|
Decimal vs. binary: why your "1 TB" drive shows 931 GB
There are two different, both technically correct, definitions of a kilobyte. The decimal definition, used by hard drive and SSD manufacturers, follows the same metric convention as kilometers or kilograms: 1 kilobyte (KB) = 1,000 bytes, 1 megabyte = 1,000,000 bytes, and so on. It's why storage is sold in clean, round numbers.
Operating systems, on the other hand, have historically calculated storage in binary, where 1 kibibyte (KiB) = 1,024 bytes — because computers address memory in powers of two, not powers of ten. The trouble is that for decades, most operating systems performed this binary math but labeled the result "KB," "MB," and "GB" anyway, as if it were the decimal version.
That mislabeling is the entire reason a drive advertised as 1 TB (1,000,000,000,000 bytes, decimal) shows up as roughly 931 GB in your file explorer: the operating system divided the same byte count using 1,024 repeatedly instead of 1,000, then attached the wrong unit name to the answer. Nothing is missing from the drive — it's the same bytes, described two different ways.
In 1998, the International Electrotechnical Commission introduced the kibi-, mebi-, gibi-, tebi- prefixes (KiB, MiB, GiB, TiB) specifically to remove this ambiguity: "KB" should mean 1,000 bytes, and "KiB" should mean 1,024. Adoption is still inconsistent — macOS switched to fully decimal reporting years ago, while Windows still shows binary math under decimal-looking labels — which is exactly why this converter lists both definitions explicitly rather than picking one.
Data transfer rate
How fast data moves — internet speed, download and upload ratesCommon conversions
Transfer rate reference
What 1 megabit per second equals in every other unit.
| Unit | Value |
|---|
Bits vs. bytes: why your 100 Mbps plan downloads at 12.5 MB/s
Internet and network speeds are conventionally advertised in bits per second (a holdover from telecommunications engineering), written with a lowercase b: Mbps, Gbps. File sizes and download speeds, on the other hand, are almost always shown in bytes per second, written with a capital B: MB/s, GB/s. Since 1 byte = 8 bits, the two numbers look very different for the exact same connection.
A "100 Mbps" internet plan has a maximum real-world throughput of about 100 ÷ 8 = 12.5 MB/s — not 100 MB/s. This isn't your connection underperforming; it's the same speed, described in the other unit. In practice actual throughput is usually a bit lower still, since some capacity goes to network overhead.