Data Size Converter
Convert data sizes across bits, decimal (SI) and binary (IEC) units at once.
Data Size Converter
Convert data sizes across bits, decimal (SI) and binary (IEC) units at once.
Data size conversion examples
MB to GB and MiB to MB
For MB to GB, select MB and enter 1000: the decimal result is 1 GB. For MiB to MB, select MiB and enter 1: the result is 1.048576 MB. Binary units follow a different scale: 1024 MiB equals 1 GiB. The tool shows both families together so you can compare the same amount of data.
Choose the unit used by your source
Check the source label and its definition before choosing a unit. In this tool, KB means 1000 bytes and KiB means 1024 bytes. If an application labels a 1024-byte unit as KB, select KiB to match its calculation. Changing the selected unit keeps the entered number and interprets it in the new unit; it does not convert the input field.
Data amount is different from transfer speed
Uppercase B means bytes; lowercase b means bits. One byte contains eight bits, so 100 Mb equals 12.5 MB. Mbps adds a time unit: 100 megabits per second equals 12.5 megabytes per second as a unit conversion. This tool converts data amounts only; it does not measure connection speed or calculate download time. Actual transfer rates depend on the connection and overhead.
FAQ
Common questions and answers about this topic.
Why does my 1 TB drive show up as 931 GB?
Nothing is missing. The manufacturer counts 1 TB as 1,000,000,000,000 bytes (decimal), while Windows divides by 1024 three times and labels the result "GB" even though it is really GiB. Same bytes, two naming conventions — this page shows both columns at once so you can see it.
My plan says 100 Mbps, so why do downloads run at 12 MB/s at best?
Network speed is quoted in bits, storage in bytes, and one byte is eight bits — so 100 Mb is 12.5 MB. This page converts the amount of information only. Real download speed also loses a few percent to protocol overhead, which no unit conversion can predict.
Is a KB 1000 bytes or 1024 bytes?
Strictly, KB is 1000 bytes and the 1024-byte unit is called KiB. In practice many operating systems still print "KB" for the 1024 version, which is where the confusion comes from. That is why this tool never merges the two — it lists them as separate columns and lets you read whichever your source uses.