Byte Converter
Convert between bytes, kilobytes, megabytes, gigabytes, and more.
Common File Sizes Reference
Text file~10 KB
MP3 song~5 MB
HD video (1hr)~4 GB
Blu-ray movie~50 GB
iPhone photo~3 MB
4K video (1hr)~20 GB
Windows install~20 GB
Steam game~50-100 GB
Decimal vs Binary Units
Storage manufacturers use decimal units (1 KB = 1000 bytes) while operating systems often display binary units (1 KiB = 1024 bytes). This is why a "500 GB" drive shows as ~465 GiB in your OS.
Decimal (SI)
- 1 KB = 1,000 bytes
- 1 MB = 1,000,000 bytes
- 1 GB = 1,000,000,000 bytes
Binary (IEC)
- 1 KiB = 1,024 bytes
- 1 MiB = 1,048,576 bytes
- 1 GiB = 1,073,741,824 bytes
Code Examples
function formatBytes(bytes, decimals = 2) {
if (bytes === 0) return '0 Bytes';
const k = 1024;
const sizes = ['Bytes', 'KiB', 'MiB', 'GiB', 'TiB'];
const i = Math.floor(Math.log(bytes) / Math.log(k));
return parseFloat((bytes / Math.pow(k, i)).toFixed(decimals)) + ' ' + sizes[i];
}Frequently Asked Questions
What's the difference between KB and KiB?
KB (kilobyte) = 1000 bytes (decimal, SI standard). KiB (kibibyte) = 1024 bytes (binary). Storage manufacturers use decimal; operating systems often use binary, causing confusion about drive sizes.
Why do my storage devices show less space than advertised?
Manufacturers use decimal units (1 GB = 1,000,000,000 bytes) while operating systems display binary units (1 GiB = 1,073,741,824 bytes). A 500 GB drive shows as ~465 GiB.