Data Storage Converter

Convert between computer data storage units including bytes, kilobytes, megabytes, gigabytes, and terabytes.

Common Data Storage Conversions

The Difference

• 1 GB (decimal) = 0.931 GiB (binary) - About 7% smaller
• 1 TB (decimal) = 0.909 TiB (binary) - About 9% smaller
• 500 GB HDD = 465.66 GiB (What Windows shows)
• 1 TB HDD = 931.32 GiB (What Windows shows)

Storage Media Examples

Real-World File Sizes

• High-res Photo (JPEG): 3-10 MB
• RAW Photo: 25-50 MB
• MP3 Song (128 kbps): ~4 MB/minute ≈ 15 MB/song
• MP3 Song (320 kbps): ~10 MB/minute ≈ 40 MB/song
• FLAC Lossless Song: 25-50 MB/song
• 4K Movie (H.264): 50-100 GB
• 4K Movie (H.265/HEVC): 25-50 GB
• HD Movie (1080p): 4-8 GB
• Video Game (Modern AAA): 50-200 GB
• Operating System: 15-30 GB
• Microsoft Office Install: 3-4 GB
• Smartphone Backup: 5-100 GB

About Data Storage Units

Computer data storage is measured in binary units where each step is a power of 2. However, storage manufacturers typically use decimal (SI) units where each step is a power of 10, leading to confusion.

Binary vs Decimal Prefixes

In 1998, the IEC introduced binary prefixes to resolve the ambiguity:

• Binary (IEC): KiB, MiB, GiB, TiB, PiB, EiB (powers of 1024)
• Decimal (SI): KB, MB, GB, TB, PB, EB (powers of 1000)

Traditional usage: KB, MB, GB were historically used to mean binary (1024-based), especially in operating systems and memory specifications. This converter provides all three notations for clarity.

Why the Confusion?

Operating Systems (Windows, macOS, Linux) use binary calculations (1024-based) because computers operate in base-2 (binary). Memory (RAM) is always specified in binary units.

Storage Manufacturers (hard drives, SSDs, USB drives) use decimal calculations (1000-based) because it's the SI standard and results in larger numbers for marketing purposes.

Result: Your "1 TB" (1,000,000,000,000 bytes) hard drive shows as 931 GiB in Windows because: 1,000,000,000,000 ÷ 1024³ = 931.32 GiB

Bits vs Bytes

• Bit (b): Smallest unit, can be 0 or 1
• Byte (B): 8 bits, can represent 256 different values (0-255)
• Nibble: 4 bits, half a byte (one hexadecimal digit)
• Word: Typically 2 bytes (16 bits) in modern systems

Important: Internet speeds are measured in bits per second (Mbps, Gbps), while file sizes are measured in bytes (MB, GB). A 100 Mbps connection downloads at ~12.5 MB/s (divide by 8).

Historical Context

Why 1024? Computers use binary (base-2) internally. 1024 = 2¹⁰, which is the closest power of 2 to 1000. Early computer scientists adopted 1024 as "kilo" for convenience, but this diverged from the SI standard where "kilo" means exactly 1000.

Common Uses

• RAM: Always binary (8 GB RAM = 8 GiB = 8,589,934,592 bytes)
• Hard Drives/SSDs: Decimal labels (1 TB = 1,000,000,000,000 bytes)
• Network Speeds: Decimal bits/sec (100 Mbps = 100,000,000 bits/sec)
• File Systems: Binary (operating systems report in GiB as "GB")
• Optical Media: Mixed (CDs use minutes, DVDs/Blu-ray use decimal GB)

Quick Calculation Tips

• To convert decimal GB to binary GiB: multiply by 0.931
• To convert binary GiB to decimal GB: multiply by 1.074
• To convert Mbps to MB/s: divide by 8
• To convert MB/s to Mbps: multiply by 8