File size converter: KB, MB, GB, TB and download time
Convert between bits, bytes, KB, MB, GB, TB — decimal and binary — and find out how long a file takes to download.
Enter a number, for example 4.7
- Bits and bytes
- bit
- B
- Decimal (1 KB = 1000 B)
- KB
- MB
- GB
- TB
- PB
- Binary (1 KiB = 1024 B)
- KiB
- MiB
- GiB
- TiB
- PiB
Runs in your browser. Nothing leaves your device.
How long will the download take?
Enter the file size and your connection speed.
Theoretical minimum at the full line speed. Real downloads are usually 10–30 % slower because of protocol overhead and server limits.
Why does a 1 TB drive show as 931 GB?
Drive makers and internet providers use decimal prefixes: 1 GB is 1 000 000 000 bytes. Windows and many programs count in powers of two — 1 GiB is 1 073 741 824 bytes — yet label the result "GB". The same terabyte drive therefore reads as about 931 GB.
The prefixes KiB, MiB, GiB and TiB (kibi-, mebi-, gibi-, tebi-) exist to remove the ambiguity: they always mean 1024. Both columns are shown above so you can see which one a given number uses.
A bit is the smallest unit and a byte is eight bits. Internet speed is quoted in megabits per second (Mbit/s), file sizes in megabytes, so a 100 Mbit/s line downloads at most 12.5 MB per second.