Data Size Converter
Convert bytes, kilobytes, megabytes, gigabytes (decimal vs. binary), and bits.
- bytes
- kb
- mb
- gb
- mib
- gib
- bits
- data
- storage
- bandwidth
About Data Size Converter
Data sizes have a notorious ambiguity baked in. A "kilobyte" can mean 1,000 bytes (the decimal SI definition) or 1,024 bytes (the binary definition, more properly called a kibibyte or KiB). Storage manufacturers use decimal because the numbers are bigger; operating systems often show binary; network speeds are quoted in bits per second, where 1 byte = 8 bits. The same file can show up as 1 GB on the box and "0.93 GB" in your file manager without anyone being wrong.
This converter shows both flavours explicitly. Enter a value once and see it in every unit at once — kilobytes (KB) and kibibytes (KiB) side by side, megabytes (MB) and mebibytes (MiB), gigabytes (GB) and gibibytes (GiB), all the way up to terabytes — plus bits for converting to and from network bandwidth.
How to use
Type a value into the input and pick its unit from the dropdown. The unit list separates decimal units (KB, MB, GB, TB — powers of 1,000) from binary units (KiB, MiB, GiB, TiB — powers of 1,024) so you can pick the right one for the context.
The conversions panel below shows the value in every other unit, with a copy button on each row. Tap any row to make that unit the new input — useful for sanity-checking "is this 100 MB or 100 MiB?" or converting a download speed (megabits per second) into a transfer time.
Frequently asked questions
What's the difference between KB and KiB?
A kilobyte (KB) is 1,000 bytes — the decimal SI definition. A kibibyte (KiB) is 1,024 bytes — the binary definition used by operating systems and RAM. The same split applies all the way up: MB vs MiB (1,000,000 vs 1,048,576), GB vs GiB (10⁹ vs 2³⁰), and so on. The discrepancy grows with each step.
Why does my 1 TB drive show as 931 GB in my OS?
Because the drive is labelled in decimal terabytes (1 TB = 10¹² bytes) but your OS reports in binary tebibytes (1 TiB = 2⁴⁰ bytes ≈ 1.0995 × 10¹²). 10¹² bytes ÷ 2³⁰ ≈ 931 GiB, which Windows and macOS report as "931 GB" using their own loose nomenclature. Nobody is wrong; the units just disagree by about 7% at terabyte scale.
How many bits in a byte?
Eight. A byte is the standard unit of digital data, and one byte equals eight bits. Network speeds are conventionally quoted in bits per second (Mbps, Gbps), while file sizes use bytes — so a 100 Mbps internet connection downloads at most about 12.5 MB/s (100 ÷ 8).
How long to download a 4 GB movie on a 100 Mbps connection?
At theoretical line speed: 4 GB = 32 Gb (gigabits) = 32,000 Mb, divided by 100 Mbps gives 320 seconds — about 5.3 minutes. Real downloads are slower due to TCP overhead, server limits, and Wi-Fi inefficiency, so plan for closer to 6–8 minutes.