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File Size Converter - Storage Unit Calculator

Online file storage size unit conversion tool

Decimal/Binary toggle
Multi-unit conversion
Common size reference
Input
Conversion Results
Bit(b)
8.0000e+9
Byte(B)
1.0000e+9
Kilobyte(KB)
1.0000e+6
Megabyte(MB)
1,000
Gigabyte(GB)
1
Terabyte(TB)
0.001
Petabyte(PB)
1.0000e-6
Quick Select
Unit Comparison
Decimal (SI)Binary (IEC)Difference
1 KB = 1,000 B1 KiB = 1,024 B2.4%
1 MB = 1,000,000 B1 MiB = 1,048,576 B4.9%
1 GB = 1,000,000,000 B1 GiB = 1,073,741,824 B7.4%
1 TB = 1,000,000,000,000 B1 TiB = 1,099,511,627,776 B10%
Usage Guide

What are File Size Units?

File sizes have two standards: decimal (SI) uses 1000 as base (KB/MB/GB), while binary (IEC) uses 1024 as base (KiB/MiB/GiB).

Decimal vs Binary

  • • Hard drive manufacturers typically use decimal
  • • Operating systems typically use binary
  • • This is why a 1TB drive shows ~931GB
  • • Difference grows with larger units

Need to convert file sizes between different units? Our file size converter helps you accurately convert between bytes, kilobytes (KB), megabytes (MB), gigabytes (GB), terabytes (TB), and their binary equivalents (KiB, MiB, GiB, TiB). Whether you are calculating hard drive capacity, estimating download times, or planning cloud storage usage, this tool provides instant conversions using both decimal (SI) and binary (IEC) standards. Understanding the difference between these standards is crucial for IT professionals, developers, and anyone working with digital storage.

Understanding Decimal vs Binary Units

Storage capacity uses two measurement standards: binary units use 1024 as the base (1 KiB = 1024 Bytes), which is the standard used internally by computers; decimal units use 1000 as the base (1 KB = 1000 Bytes), commonly used by hard drive manufacturers. This is why a 1TB hard drive shows approximately 931 GiB in your operating system. Our converter provides both results to eliminate confusion and help you understand the real capacity of your storage devices.

Common Conversion Scenarios

  • Calculate cloud storage costs and quota usage accurately
  • Estimate memory requirements for programs and containers
  • Calculate network transfer speeds and file download times
  • Plan database and log file storage capacity
  • Compare advertised vs actual hard drive capacity

Quick Reference Chart

1 KB = 1,000 Bytes | 1 KiB = 1,024 Bytes; 1 MB = 1,000 KB | 1 MiB = 1,024 KiB; 1 GB = 1,000 MB | 1 GiB = 1,024 MiB; 1 TB = 1,000 GB | 1 TiB = 1,024 GiB; 1 PB = 1,000 TB | 1 PiB = 1,024 TiB

Why File Size Conversion Matters

Accurate file size conversion is essential in many professional contexts. System administrators need to plan storage capacity, developers must optimize application memory usage, and network engineers calculate bandwidth requirements. Misunderstanding the difference between decimal and binary units can lead to capacity planning errors, unexpected storage shortages, and incorrect cost estimates for cloud services.

FAQ

Q: Why does my 500GB hard drive only show 465GB on my computer?

A: Hard drive manufacturers use decimal calculation (500 GB = 500,000,000,000 Bytes), while operating systems display using binary units (approximately 465 GiB). This is due to different measurement standards, not a defective drive. The actual storage capacity is the same.

Q: When should I use binary units (KiB, MiB)?

A: Use binary units when dealing with RAM capacity, actual file system usage, and program memory allocation. Use decimal units when discussing network bandwidth and manufacturer-stated hard drive capacity. Most programming contexts and operating systems use binary internally.

Q: How long does it take to download a 1 GB file at 1 Mbps?

A: 1 Mbps = 1,000,000 bits/second = 125,000 Bytes/second. Downloading 1 GB (1,000,000,000 Bytes) takes approximately 8,000 seconds, or about 2 hours and 13 minutes. Note that network speed is measured in bits, while file size is measured in bytes, and 1 Byte = 8 bits.

Q: What is the difference between MB and MiB?

A: MB (Megabyte) uses the decimal standard where 1 MB = 1,000,000 Bytes. MiB (Mebibyte) uses the binary standard where 1 MiB = 1,048,576 Bytes. The difference is about 4.9%, which becomes more significant with larger units.