Data Size Converter — Bits, Bytes, KB, MB, GB, TB

About the Data Size Converter

This free online tool instantly converts data sizes between bits, bytes, kilobytes, megabytes, gigabytes, terabytes, petabytes, and exabytes. All calculations happen in your browser — no data is sent to any server.

Binary vs. Decimal (1024 vs. 1000)

There are two competing standards for data size prefixes. The decimal (SI) standard used by hard drive manufacturers and network equipment defines 1 KB as 1,000 bytes, 1 MB as 1,000,000 bytes, and so on. The binary (IEC) standard — used by operating systems like Windows for RAM and file sizes — defines 1 KiB as 1,024 bytes, 1 MiB as 1,048,576 bytes, and so on. This is why a hard drive advertised as 1 TB shows up as roughly 931 GiB in Windows.

Key Data Size Facts

• 1 Byte = 8 Bits — the fundamental unit of digital storage.
• Decimal: 1 KB = 1,000 B | 1 MB = 1,000,000 B | 1 GB = 1,000,000,000 B
• Binary: 1 KiB = 1,024 B | 1 MiB = 1,048,576 B | 1 GiB = 1,073,741,824 B
• 1 TB (decimal) ≈ 931 GiB (binary) — explains the "missing space" on drives.
• A standard DVD holds 4.7 GB; a single-layer Blu-ray disc holds 25 GB.
• 1 Petabyte = 1,000 Terabytes = about 500 billion pages of text.

Common Data Size Conversions

• 1 MB = 1,000 KB = 8,000,000 bits (decimal)
• 1 GB = 1,024 MB (binary) or 1,000 MB (decimal)
• 1 TB = 1,024 GB (binary) or 1,000 GB (decimal)
• Internet speed is measured in Mbps (megabits per second) — 8 Mbps downloads 1 MB/s.
• A typical MP3 song is around 4 MB; a 4K movie can be 50–100 GB.

How to Use This Tool

Enter any numeric value, choose the source unit from the dropdown, and select either Decimal (1000-based) or Binary (1024-based) mode. The table instantly shows the equivalent in every other unit. Use the quick presets for common reference sizes, or click Swap to switch to the next unit while keeping the equivalent value.