About this file size converter
File sizes are counted in two different ways. Drive makers, networks, and the SI standard use decimal prefixes, where a kilobyte is 1,000 bytes and a gigabyte is a billion bytes. Operating systems and memory often count in powers of two, where a kibibyte (KiB) is 1,024 bytes and a gibibyte (GiB) is 1,073,741,824 bytes, though Windows still labels them KB, MB, and GB. That is why a 1 TB drive shows about 931 GB on a computer. This converter shows any size in both systems side by side, from single bits up to exabytes.
How to convert file sizes
- Enter the size. Type a number, or press an example such as DVD (4.7 GB).
- Choose the unit and system. Pick the unit, then Decimal if it comes from a drive label or download page, or Binary for memory and many operating systems.
- Press Convert size. Read the size in every unit of both systems and copy the value you need.
Frequently asked questions
Why does my 1 TB drive show only 931 GB?
The drive maker counts 1 TB as 1,000,000,000,000 bytes, but Windows divides by 1,024 three times and calls the result GB. The same bytes come out as about 931 binary gigabytes (GiB).
Is a kilobyte 1,000 or 1,024 bytes?
By the SI and IEC standards, a kilobyte (KB) is 1,000 bytes and a kibibyte (KiB) is 1,024 bytes. In everyday use KB is still often used for 1,024, which is why both systems are shown.
What is the difference between bits and bytes?
A byte is 8 bits. Internet speeds are usually given in bits per second (Mbps), while file sizes are in bytes, so a 100 Mbps connection moves at most 12.5 megabytes per second.
How big is a typical file?
A short email is a few kilobytes, an MP3 song 3 to 5 MB, a phone photo 2 to 5 MB, an hour of HD video 3 to 5 GB, and a modern video game 50 to 150 GB.