File Size Converter
Runs in your browser — your data is never uploaded.
Convert between bytes, KB, MB, GB and TB — and see both conventions at once, because they disagree and that disagreement is usually why you are here. Your operating system counts in 1024s; drive manufacturers print 1000s. That is the entire reason a “1 TB” disk shows up as about 931 GB, and showing only one number would just pick a side of the confusion.
How to use File Size Converter
- 1
Enter the size and pick the unit it is in.
- 2
Pick the unit you want it in.
- 3
Read both the binary (1024) and decimal (1000) results.
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Frequently asked questions
Why does my 1 TB drive show as 931 GB?+
The manufacturer sold you 1,000,000,000,000 bytes, counting in powers of 1000. Windows divides by 1024 three times and reports 931 GB. Nothing is missing — the two are counting the same bytes with different units.
What are KiB, MiB and GiB?+
The unambiguous names for the 1024-based units. 1 MiB is exactly 1,048,576 bytes; 1 MB should strictly be 1,000,000. Most operating systems say “MB” while showing MiB, which is where the ambiguity comes from in the first place.
Which should I use for an upload limit?+
Assume the smaller, decimal interpretation when you are close to a limit. A service advertising a 25 MB cap may well mean 25,000,000 bytes, and a file that is 25 MiB would be rejected.