File Size Converter

1. Enter a numeric value in the input field.
2. Select the source unit (Bytes, KB, MB, GB, TB, or PB).
3. Toggle between binary (1024) and decimal (1000) standards.
4. View all equivalent values at once in the results grid, including bit values for bandwidth context.
5. Click the copy button next to any result to copy it to your clipboard.

What Are File Size Units?

File sizes are measured in bytes and their multiples. A byte consists of 8 bits and is the fundamental unit of digital storage. As files and storage devices grow larger, we use prefixed units like kilobytes, megabytes, gigabytes, and terabytes to express sizes in a readable way. However, there are two competing standards for these prefixes, which creates confusion: the binary standard (base 1024) used by operating systems and memory, and the decimal standard (base 1000) used by storage manufacturers and networking equipment.

Binary vs Decimal: Why Sizes Differ

In the binary standard (IEC), 1 KiB = 1,024 bytes, 1 MiB = 1,048,576 bytes, and 1 GiB = 1,073,741,824 bytes. In the decimal standard (SI), 1 KB = 1,000 bytes, 1 MB = 1,000,000 bytes, and 1 GB = 1,000,000,000 bytes. This is why a 500 GB hard drive shows approximately 465 GiB in your operating system. Storage manufacturers use the decimal standard (which produces larger-sounding numbers), while Windows reports sizes using the binary standard. macOS switched to decimal reporting in 2009 to reduce confusion.

Common Use Cases

• Understanding why advertised storage sizes differ from what your OS shows
• Calculating bandwidth requirements (converting between bytes and bits per second)
• Estimating download times based on file size and connection speed
• Configuring upload limits for web applications and APIs
• Planning cloud storage and data transfer costs

Bytes vs Bits in Networking

Network speeds are measured in bits per second (bps), while file sizes are measured in bytes. Since 1 byte equals 8 bits, a 100 Mbps internet connection can transfer roughly 12.5 MB per second under ideal conditions. Real-world throughput is lower due to protocol overhead, latency, and congestion. When comparing download speeds to file sizes, always remember to divide the advertised speed by 8 to convert from megabits to megabytes. This tool includes bit-based conversions to help bridge this gap.

For related conversions, try the Number Base Converter for hexadecimal and binary arithmetic, or the Unit Converter for length, weight, and temperature conversions.