Home / Unit / Data Size
Data Size Converter
Convert between Bytes, KB, MB, GB, and TB instantly. Understand file sizes, storage capacity, and the difference between binary and decimal systems.
The Confusing World of Data Storage
You buy a 1TB hard drive. Windows shows 931GB. You feel scammed. But you're not—you just encountered the binary vs decimal problem.
Binary (What Computers Use)
- 1 Kilobyte (KB) = 1,024 bytes
- 1 Megabyte (MB) = 1,024 KB = 1,048,576 bytes
- 1 Gigabyte (GB) = 1,024 MB = 1,073,741,824 bytes
- 1 Terabyte (TB) = 1,024 GB = 1,099,511,627,776 bytes
Decimal (What Manufacturers Use)
- 1 Kilobyte (KB) = 1,000 bytes
- 1 Megabyte (MB) = 1,000 KB = 1,000,000 bytes
- 1 Gigabyte (GB) = 1,000 MB = 1,000,000,000 bytes
- 1 Terabyte (TB) = 1,000 GB = 1,000,000,000,000 bytes
⚠️ Why Your 1TB Drive Shows 931GB
Manufacturers sell "1TB" = 1,000,000,000,000 bytes. Windows reads this as 1,000,000,000,000 ÷ 1,073,741,824 (binary GB) = 931GB. The missing 69GB didn't vanish—it's just a measurement difference. You're getting exactly what you paid for in raw bytes.
Real-World File Sizes
Text: 1 page of plain text = ~2KB. War and Peace = ~3.5MB.
Images: iPhone photo = 2-5MB. RAW photo = 25-50MB.
Music: 1 minute MP3 = ~1MB. Album (15 songs) = ~60MB.
Video: 1 minute 1080p = ~100MB. 4K movie (2 hours) = ~15GB.
Games: Modern AAA game = 50-150GB. Call of Duty = ~200GB+.
💡 Quick Tip
If you're streaming, data is measured per second. Netflix 4K uses ~25Mbps (megabits per second). That's 3.125 MB/s (megabytes). A 2-hour movie = 3.125 × 7,200 seconds = ~22.5GB of data used.
Reviewed by Dr. Alex M.
Ph.D. in Computer Science
Expert in data storage systems and digital measurement.
Frequently Asked Questions
Is 1 KB equal to 1000 or 1024 bytes?
Both are correct, depending on context. In binary system (used by operating systems), 1 KB = 1024 bytes. In decimal system (used by storage manufacturers), 1 KB = 1000 bytes. This calculator uses the binary system (1024), which is why a 500GB hard drive shows as ~465GB in Windows.
How many GB is 1 TB?
1 Terabyte (TB) = 1,024 Gigabytes (GB) in the binary system. In decimal, 1 TB = 1,000 GB. Modern operating systems use binary, so a 1TB drive holds 1,024 GB.
Why does my hard drive show less space than advertised?
Hard drive manufacturers use decimal (1 GB = 1,000,000,000 bytes) while operating systems use binary (1 GB = 1,073,741,824 bytes). A 500GB drive advertised contains 500,000,000,000 bytes, which equals only ~465GB in Windows. This is not a scam—it's two different measurement systems.