Data Size Converter
Convert data sizes across bits, decimal (SI) and binary (IEC) units at once.
Enter a size in any unit and all three families update instantly — bits, decimal KB/MB/GB and binary KiB/MiB/GiB side by side. Showing them together is the point, because that gap is why a 1 TB drive reads as 931 GB.
Data Size Converter
Convert data sizes across bits, decimal (SI) and binary (IEC) units at once.
About this tool
Enter a size in any unit and all three families update instantly — bits, decimal KB/MB/GB and binary KiB/MiB/GiB side by side. Showing them together is the point, because that gap is why a 1 TB drive reads as 931 GB.
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.