Data Size Converter

Convert between bytes, KB, MB, GB, TB and more.

Unit & Calculator

The Data Size Converter translates between digital storage units — Bytes, Kilobytes, Megabytes, Gigabytes, Terabytes, and Petabytes — in both binary (base-1024) and decimal (base-1000) systems. Understanding data sizes is essential for developers, system administrators, and everyday users who need to estimate storage requirements, compare disk capacities, or calculate bandwidth usage. The binary/decimal distinction explains why a "1 TB" hard drive shows only ~931 GB in your operating system. This tool makes the conversion transparent and instant, running entirely in your browser with no data sent to any server.

Uncheck for decimal (1000)

About Data Size Converter

Data sizes are expressed using two competing conventions: binary (base-1024), where 1 KiB = 1,024 bytes, used by operating systems, RAM specifications, and file systems; and decimal (base-1000), where 1 KB = 1,000 bytes, used by drive manufacturers, network specifications, and many international standards. This discrepancy causes confusion — a 500 GB SSD (decimal) appears as approximately 465 GiB (binary) in Windows. This tool converts between Bytes, KB, MB, GB, TB, and PB in both modes, showing all equivalent values at once. Enter a value, select the source unit, toggle binary or decimal, and see the conversions instantly. Everything runs in JavaScript on your device with no server round-trips.

How to Use Data Size Converter

  1. Enter the numeric Value you want to convert.
  2. Select the From unit (e.g., Megabytes).
  3. Check Binary (1024) for operating-system-style units (KiB/MiB/GiB) or uncheck for decimal (1000-based KB/MB/GB).
  4. Read the equivalent values in all other units from the Results grid.

Key Features

  • Converts between Bytes, KB, MB, GB, TB, and PB simultaneously
  • Toggle between binary (1024-based) and decimal (1000-based) conventions
  • Shows all equivalent values at once in a clear results grid
  • Instant conversion — results update as you type
  • 100% browser-based — no data uploaded, no server dependency
  • Useful companion to the Unit Converter for other measurement types

When to Use This Tool

  • Understanding why a "1 TB" drive shows ~931 GB in Windows or macOS
  • Converting file sizes for documentation, specifications, or technical reports
  • Estimating storage or bandwidth requirements in consistent units
  • Checking data caps or quotas against actual usage in the correct convention
  • Comparing storage device capacities across different manufacturers

Technical Details

In binary mode: 1 KiB = 1,024 B, 1 MiB = 1,024 KiB (1,048,576 B), 1 GiB = 1,024 MiB (1,073,741,824 B), 1 TiB = 1,024 GiB, 1 PiB = 1,024 TiB. In decimal mode: 1 KB = 1,000 B, 1 MB = 1,000 KB (1,000,000 B), 1 GB = 1,000 MB (1,000,000,000 B), 1 TB = 1,000 GB, 1 PB = 1,000 TB. The tool first converts the input to bytes, then divides by the appropriate factor for each target unit. JavaScript floating-point precision is sufficient for values up to petabytes in everyday use. Results are rounded to a sensible number of decimal places for readability.

Conclusion

The Data Size Converter eliminates confusion between binary and decimal data units by providing instant, accurate conversions across all common storage sizes. It is a must-have reference for developers, sysadmins, and anyone working with digital storage — all running privately in your browser.

Frequently Asked Questions

What is the difference between binary and decimal?
Binary (base-1024): 1 KiB = 1,024 B, used by operating systems and RAM. Decimal (base-1000): 1 KB = 1,000 B, used by drive manufacturers and networking. A "1 TB" drive (decimal) shows ~931 GB (binary) in Windows because of this difference.
Is this tool accurate for large values?
Yes. Conversions use standard formulas and JavaScript number precision is more than sufficient for values up to petabytes in everyday use.
Does it run offline?
Yes. All conversion math runs in your browser. No data is sent to a server, so you can use it without an internet connection after the page has loaded.
Why do I see different sizes on my drive than on the box?
Drive makers label capacity in decimal (e.g., 1 TB = 1,000,000,000,000 bytes). Your OS reports in binary (1 TiB = 1,099,511,627,776 bytes). So 1 TB (decimal) ≈ 0.91 TiB (binary), which appears as roughly 931 GB in your file manager.