File Size Converter
Convert instantly between bytes, KB, MB, GB, TB. Free, fast, and no installation required - precise calculations for your storage needs.
Bytes (B)
Kilobytes (KB)
Megabytes (MB)
Gigabytes (GB)
Terabytes (TB)
Binary system
1 KB = 1024 bytes (computing standard)
File Size Converter: Convert Between Bytes, KB, MB, GB and TB
The File Size Converter is a free tool that instantly converts file sizes between all common units. From bytes to terabytes, this calculator handles both binary (KiB, MiB, GiB) and decimal (KB, MB, GB) units, helping developers, system administrators, and anyone working with storage understand and convert file sizes accurately.
File size units can be confusing: is 1 KB equal to 1000 or 1024 bytes? The answer depends on whether you're using decimal (SI) or binary (IEC) standards. Our converter supports both systems and shows you all conversions simultaneously, eliminating confusion.
💡 Why File Size Conversion Matters
Hard drive manufacturers use decimal units (1 GB = 1,000,000,000 bytes), while operating systems often use binary units (1 GiB = 1,073,741,824 bytes). This discrepancy explains why your "500 GB" drive shows only 465 GB in Windows!
This tool helps you understand and convert between both systems, making it easier to plan storage, estimate transfer times, and communicate file sizes accurately.
🎯 Typical Use Case:
You need to upload a 150 MB file but your API has a 100 MiB limit. Is that going to work? With this converter, you quickly see that 150 MB (decimal) = 143.05 MiB (binary), so your upload will succeed.
🔧 Practical Use Cases
💾 Storage Planning
Calculate how many files fit on a drive or estimate storage costs in cloud services.
500 GB drive ÷ 4.7 GB per movie = 106 movies
📡 Transfer Time Estimation
Convert file sizes to bits for bandwidth calculations.
100 MB = 800 Mb ÷ 100 Mbps = 8 seconds
🔧 API Limits
Check if your file meets upload limits specified in different units.
AWS Lambda: 50 MB (decimal) payload limit
📊 Log Analysis
Convert byte counts from logs to human-readable sizes.
1073741824 bytes = 1 GiB = 1.07 GB
✨ Binary vs Decimal Units
Decimal (SI)
Base 1000 - Used by storage manufacturers
- 1 KB = 1,000 bytes
- 1 MB = 1,000,000 bytes
- 1 GB = 1,000,000,000 bytes
- 1 TB = 1,000,000,000,000 bytes
Binary (IEC)
Base 1024 - Used by operating systems
- 1 KiB = 1,024 bytes
- 1 MiB = 1,048,576 bytes
- 1 GiB = 1,073,741,824 bytes
- 1 TiB = 1,099,511,627,776 bytes
❓ Frequently Asked Questions (FAQ)
Why does my hard drive show less space than advertised?
Manufacturers use decimal units (1 GB = 1 billion bytes), while Windows uses binary units (1 GiB = 1.07 billion bytes). A "500 GB" drive actually has 500,000,000,000 bytes, which equals 465.66 GiB as shown in Windows.
Should I use MB or MiB?
Use MiB/GiB when discussing RAM, file system sizes, or programming. Use MB/GB for storage capacities and data transfer. When in doubt, specify which system you mean to avoid confusion.
What about bits vs bytes?
1 byte = 8 bits. Network speeds are usually in bits (Mbps), while file sizes are in bytes (MB). To convert download speed to file transfer time: divide file size (MB) by speed (Mbps) × 8.