File Size Unit Converter

Use this tool to instantly and mathematically convert any file size into every other unit of digital measurement. Whether you need to know exactly how many Megabytes (MB) are in a Gigabyte (GB), or how many raw bits are in a Terabyte, this calculator handles the exact math for you.

This is exceptionally useful when estimating server bandwidth requirements, allocating database storage limits, or determining exactly how long a massive file transfer will take over a network connection.

How it works

Digital storage math is notoriously confusing because the technology industry simultaneously uses two completely different counting systems: Decimal (Base-10) and Binary (Base-2).

Decimal (Base-10): This is the system hard drive manufacturers (like Western Digital or Seagate) and Apple's macOS use. In this system, exactly 1,000 Kilobytes = 1 Megabyte. When you buy a "1 Terabyte" hard drive, you are getting exactly 1,000,000,000,000 bytes of storage.

Binary (Base-2): This is the system that Microsoft Windows and computer memory (RAM) use. In this system, computers calculate in powers of 2, meaning 1,024 Kilobytes (technically called Kibibytes) = 1 Megabyte. This discrepancy is why your brand new "1 Terabyte" hard drive shows up as only "931 GB" when you plug it into a Windows PC. Windows is dividing by 1024, not 1000.

Bits vs Bytes: A single Byte is composed of 8 Bits. Internet service providers always advertise speeds in Bits (e.g., 100 Megabits per second or 100 Mbps). You must divide that number by 8 to find out your actual download speed in Megabytes (12.5 MB/s).

Frequently asked questions