File Size Converter
Convert file sizes between different storage units including bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes.
What is the difference between KB and KiB (binary vs decimal)?
Two measurement systems exist: Decimal (SI units): 1 KB = 1000 bytes, 1 MB = 1000 KB = 1,000,000 bytes, 1 GB = 1000 MB = 1 billion bytes. Used by: Hard drive manufacturers, storage device marketing, networking speeds. Binary (IEC units): 1 KiB (kibibyte) = 1024 bytes, 1 MiB (mebibyte) = 1024 KiB = 1,048,576 bytes, 1 GiB (gibibyte) = 1024 MiB. Used by: Operating systems (Windows, macOS), RAM specifications, file systems. Marketing confusion: 500 GB hard drive = 465 GiB actual space (why drives appear smaller). Our calculator uses decimal (1000-based) standard most common for storage.
How do file sizes affect storage and transfer times?
File size impacts: Storage capacity: 256 GB SSD holds ~256,000 MB, 1 TB drive = 1000 GB = 1 million MB. Typical files: High-res photo (5-20 MB), MP3 song (3-10 MB), HD movie (4-8 GB), 4K movie (25-100 GB), MS Word doc (50-500 KB), PDF (100 KB-10 MB). Transfer times: 1 GB file at 100 Mbps internet = ~80 seconds. 1 GB via USB 2.0 (480 Mbps) = ~20 seconds. 1 GB via USB 3.0 (5 Gbps) = ~2 seconds. Cloud upload 10 MB at 10 Mbps = ~8 seconds. Compression reduces sizes 50-90% (ZIP, RAR).
What are common file sizes for different media types?
Typical file sizes by category: Images: JPEG photo (2-10 MB), PNG screenshot (500 KB-5 MB), RAW photo (20-60 MB), GIF (100 KB-5 MB). Videos: 1-min 1080p (50-150 MB), 1-min 4K (200-500 MB), HD movie 2hr (4-8 GB), 4K movie 2hr (25-100 GB). Audio: MP3 3-min song (3-7 MB), FLAC lossless (30-50 MB), podcast 1hr (50-100 MB). Documents: Word doc (50-500 KB), PDF book (1-20 MB), PowerPoint (5-50 MB). Software: Mobile app (50-500 MB), PC game (20-150 GB), OS install (5-20 GB).
How much storage do I need for my files?
Storage requirements estimation: Light users (email, browsing): 256 GB sufficient - ~50,000 photos or 1000 hours music. Average users (photos, music, documents): 512 GB-1 TB - ~100,000 photos, 2000 movies, or 200,000 songs. Power users (video editing, gaming): 2-4 TB - store 50+ games (40 GB each), 4K video projects. Professionals (photography, video production): 4-20 TB - RAW photos (50 MB each), uncompressed 4K footage. Cloud backup: Consider 2-5 TB cloud storage for critical files. Rule of thumb: Buy 2x current usage for growth. External drives cheaper than internal for archives.
Why does my 1 TB drive show less available space?
Drive capacity discrepancy causes: Decimal vs binary: Manufacturers use 1 TB = 1000 GB (decimal). OS uses 1 TB = 1024 GB (binary). Result: 1 TB drive = 931 GB actual space (1,000,000,000,000 / 1,073,741,824). Pre-installed software: Recovery partitions (10-20 GB), OS files (20-50 GB), manufacturer software (1-5 GB). File system overhead: NTFS, FAT32, exFAT reserve space for metadata (1-3%). Example: 500 GB drive actual space = ~465 GB - 20 GB (OS/recovery) = 445 GB usable. This is normal, not defective. Buy larger than needed to account for overhead.
What file sizes work best for email attachments?
Email attachment size limits by provider: Gmail: 25 MB limit (use Google Drive for larger). Outlook/Hotmail: 20 MB limit (OneDrive for bigger files). Yahoo: 25 MB limit. Corporate email: Often 10 MB limit. Best practices: Keep under 10 MB for reliability (faster sending/receiving). Compress large files - ZIP reduces 50-70%. Use cloud sharing for 25+ MB files (Dropbox, WeTransfer, Google Drive). Split large files if necessary. Images: Resize to 1920px width, compress to 500 KB-2 MB. PDFs: Compress using online tools, reduce from 20 MB to 2 MB typical. Videos: Never email raw video - use YouTube, Vimeo unlisted links.
How do I reduce file sizes effectively?
File compression strategies by type: Images: Resize dimensions (4K to 1080p saves 75%), convert PNG to JPEG (saves 50-80%), use compression tools (TinyPNG, JPEGmini reduce 50-70%), reduce quality 90→80% (minimal visual loss, 30% smaller). Videos: Lower resolution (4K→1080p saves 75%), reduce bitrate (H.265/HEVC codec 50% smaller than H.264), trim unnecessary footage. Documents: Remove embedded images/fonts, convert to PDF with compression, remove metadata. Compression formats: ZIP (universal, 50-70% reduction), RAR (better compression, proprietary), 7z (best compression, free). Cloud auto-compression available on Google Photos, Dropbox.