Productive ToolboxFile Size Converter
Convert file sizes instantly between Bytes, KB, MB, GB, TB, and PB using binary (1024) or decimal (1000) standards.
File Size Converter
Convert between Bytes, KB, MB, GB, TB, and PB using binary (1024) or decimal (1000) standards. We do not collect or store what you enter.
Conversion Settings
1 KB = 1,024 Bytes — used by OS and filesystems
Press Esc to reset
Conversion Summary
Quick Presets
All Conversions
💡 Binary vs Decimal — What's the difference?
Binary (1024-based)
Used by Windows, RAM and many Linux tools. 1 KiB = 1,024 bytes; Windows still labels it "KB".
Decimal (1000-based)
Used by drive makers, macOS (since 10.6), iOS and network speeds. 1 KB = 1,000 bytes. A 1 TB drive is about 931 GiB.
Related tools
What This File Size Converter Does
Enter a size and the converter shows it in bytes, KB, MB, GB, TB and PB at once, in either binary units (1 KB = 1,024 bytes) or decimal units (1 KB = 1,000 bytes). It also shows how the same size appears in Windows and macOS, which use different units, and how long the file takes to download or upload at your connection speed.
That difference is why a new 1 TB drive shows up as 931 GB in Windows, and why a file can look larger on a Mac than on a PC: the bytes are identical, only the unit changes.
How to Use the File Size Converter
- 1Enter a size: Type any number into File size; decimals and very large values work.
- 2Pick the unit: Choose bytes, KB, MB, GB, TB or PB, or click a preset such as 100 MB or 1 TB.
- 3Choose binary or decimal: Binary (1,024) matches Windows and RAM; decimal (1,000) matches drive labels, macOS and network speeds.
- 4Read every unit at once: The results table lists the size in all six units, with the exact byte count.
- 5See how it shows up and how long it takes: Compare how Windows and macOS display the size, and set your connection speed in Mbps to see the download or upload time.
- 6Copy or export: Copy a single value or the share-ready line, or download the full result as text or CSV.
Binary and Decimal Units, and Typical Sizes
| Unit | Decimal | Binary |
|---|---|---|
| Kilobyte | KB = 1,000 B | KiB = 1,024 B |
| Megabyte | MB = 1,000,000 B | MiB = 1,048,576 B |
| Gigabyte | GB = 1,000,000,000 B | GiB = 1,073,741,824 B |
| Terabyte | TB = 10¹² B | TiB = 1,099,511,627,776 B |
| Petabyte | PB = 10¹⁵ B | PiB ≈ 1.126 × 10¹⁵ B |
| Item | Rough size |
|---|---|
| A page of plain text | about 2–4 KB |
| A 12-megapixel JPEG photo | about 3–5 MB |
| A 4-minute song at 256 kbps | about 7.7 MB |
| One hour of HD streaming at 5 Mbps | about 2.25 GB |
| A modern video game | 50–150 GB |
Approximate; real files vary with resolution, compression and length.
Frequently Asked Questions
Why does my 1 TB drive show 931 GB on Windows?
Drive makers count in decimal: 1 TB = 1,000,000,000,000 bytes. Windows divides by 1,024 three times but still writes GB, so it shows 1,000,000,000,000 ÷ 1,073,741,824 ≈ 931 GB. Nothing is missing; it is the same number of bytes in a different unit.
Why does the same file look bigger on a Mac than on Windows?
Since macOS 10.6, Finder counts 1 KB as 1,000 bytes, while Windows Explorer counts 1 KB as 1,024 bytes. A file of 1,500,000,000 bytes shows as 1.5 GB on a Mac and about 1.4 GB on Windows.
What is the difference between MB and MiB?
An MB (megabyte) is 1,000,000 bytes. A MiB (mebibyte) is 1,048,576 bytes, or 1,024 × 1,024. The IEC binary prefixes KiB, MiB and GiB were introduced to tell the two apart, but in everyday use "MB" can mean either.
Which standard should I use?
Use binary (1,024) to match what Windows shows, for RAM, and for most programming. Use decimal (1,000) for drive and SSD capacities, cloud storage plans, macOS and iOS, and anything tied to network speed.
How long does it take to download a file?
Multiply the size in bytes by 8 to get bits, then divide by your speed in bits per second. A 5 GB (decimal) file on a 100 Mbps connection takes 5,000,000,000 × 8 ÷ 100,000,000 = 400 seconds, about 6 minutes 40 seconds, at full speed. Real downloads are slower because of protocol overhead and shared connections.
What is the difference between Mbps and MB/s?
Mbps is megabits per second, the unit internet providers use. MB/s is megabytes per second, which download managers often show. One byte is 8 bits, so 100 Mbps is at most 12.5 MB/s.
Is my data sent anywhere?
No. We do not collect or store what you enter. Any history the tool keeps is visible only to you.
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