Decimal vs. binary units
Data sizes come in two families. Decimal units (KB, MB, GB) step by 1,000 and are used on storage labels and network speeds. Binary units (KiB, MiB, GiB) step by 1,024 and are what operating systems often report. This tool includes both, converting everything through bytes.
Why your drive looks smaller
A "1 TB" drive is 1,000,000,000,000 bytes (decimal), but your OS may show it as about 931 GiB (binary). Nothing is missing — it's the two counting systems. Converting between TB and TiB here shows exactly where the difference comes from.
Bits vs. bytes
Network speeds are in bits (Mbps), files in bytes (MB). One byte is eight bits, so a 100 Mbps connection moves about 12.5 MB per second. Mixing the two is a classic source of confusion the converter clears up.
Frequently asked questions
Why is my 1 TB drive shown as 931 GB?
Your OS uses binary units (GiB) while the label uses decimal (GB). 1 TB equals about 931 GiB — same bytes, different counting.
How many bits in a byte?
Eight. To convert a Mbps speed to MB per second, divide by eight.
How many MB in a GB?
1,024 MB in binary, or 1,000 MB in the decimal system drive makers use.
What is the difference between a bit and a byte?
A byte is 8 bits. File sizes use bytes; connection speeds usually use bits.
How many GB in a TB?
1,024 GB (binary) or 1,000 GB (decimal).