File Size Calculator
Convert file sizes between bits, bytes, KB, MB, GB, TB, and PB. Supports binary (1024) and decimal (1000) standards with IEC prefixes.
Conversion Results
| Unit | Abbreviation | Value |
|---|---|---|
| bits | bit | 8,388,608 |
| bytes | B | 1,048,576 |
| kibibytes | KiB | 1,024 |
| mebibytes | MiB | 1 |
| gibibytes | GiB | 0.000977 |
| tebibytes | TiB | 9.5367e-7 |
| pebibytes | PiB | 9.3132e-10 |
Privacy & Processing
Convert between bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes. Toggle between binary (IEC, base 1024) and decimal (SI, base 1000) standards. All calculations run locally in your browser.
File Size Calculator & Converter – Convert Bytes, KB, MB, GB Instantly
A file size calculator converts storage values between units like bits, bytes, kilobytes, megabytes, gigabytes, terabytes, and petabytes. This free online file size converter helps you translate any value into every supported unit in real time, whether you are checking upload limits, comparing drive capacity, or explaining storage to a client. Toggle between binary (1024-based IEC) and decimal (1000-based SI) standards to match Windows, macOS, or storage manufacturer labeling.
How to convert file sizes
- Enter the numeric file size in the input field at the top of the calculator.
- Select the unit that matches your starting value (bits, bytes, KB, MB, GB, TB, or PB).
- Toggle the standard switch to choose binary (1024, KiB/MiB/GiB) or decimal (1000, KB/MB/GB).
- Read the conversion results table, which updates instantly as you type.
- Click "Copy Results" to copy all unit conversions, or "Copy Share Link" to save your current calculation as a shareable URL.
What is the difference between binary and decimal file sizes?
Binary file sizes use powers of 1024 because computers operate in base two. One binary megabyte (mebibyte, MiB) equals 1,048,576 bytes. Decimal file sizes use powers of 1000 following the metric system. One decimal megabyte (MB) equals 1,000,000 bytes. Storage drive manufacturers typically label capacity in decimal terabytes, while Windows and many file managers still display binary units. That is why a 2 TB drive may appear as approximately 1.82 TiB in Windows Explorer.
The International Electrotechnical Commission (IEC) introduced binary prefixes—kibibyte (KiB), mebibyte (MiB), gibibyte (GiB)—to reduce confusion. When converting file sizes for technical documentation, software development, or system administration, always confirm which standard your audience expects before publishing results.
How do you convert bytes to kilobytes?
To convert bytes to kilobytes in binary, divide the byte count by 1024. For example, 5,242,880 bytes ÷ 1024 = 5,120 KiB (binary kilobytes). In decimal, divide by 1000 instead. To convert bits to bytes, divide by 8 because each byte contains 8 bits. To convert kilobytes to megabytes, divide by 1024 again in binary or by 1000 in decimal. This calculator performs all of these conversions automatically across every supported unit.
How do you convert megabytes to gigabytes?
Divide megabytes by 1024 to get gigabytes in binary (MiB to GiB), or divide by 1000 for decimal (MB to GB). For example, 1024 MiB equals 1 GiB, while 1000 MB equals 1 GB. Video files, disk images, and backup archives are commonly measured in gigabytes or terabytes, so knowing which standard applies prevents costly misinterpretation of storage requirements.
File size prefix reference table
The table below compares decimal (SI/metric) prefixes with IEC binary prefixes used in computing. Use this reference when reading documentation, datasheets, or operating system reports that mix both naming conventions.
| Metric (SI) | Size | IEC Binary | Size |
|---|---|---|---|
| kilobyte (kB) | 10³ | kibibyte (KiB) | 2¹⁰ |
| megabyte (MB) | 10⁶ | mebibyte (MiB) | 2²⁰ |
| gigabyte (GB) | 10⁹ | gibibyte (GiB) | 2³⁰ |
| terabyte (TB) | 10¹² | tebibyte (TiB) | 2⁴⁰ |
| petabyte (PB) | 10¹⁵ | pebibyte (PiB) | 2⁵⁰ |
Common file sizes by type
Understanding typical file sizes helps you estimate storage needs, email attachment limits, and upload times. These ranges are approximate and vary based on compression, quality settings, and content complexity.
- Text File (TXT) — 1–2 KB (Tiny)
- Word Document (DOC/DOCX) — 50–300 KB (Small)
- Photo (JPG, 12 MP) — 3–5 MB (Medium)
- MP3 Audio (full song) — 3–10 MB (Medium)
- SD Video (1–1.5 hr) — 700 MB–1 GB (Large)
- Full HD Video (1–1.5 hr) — 7–10 GB (Large)
Text files are among the smallest because size equals character count. Word documents add formatting overhead. Photos from modern cameras range from a few megabytes to tens of megabytes depending on resolution and compression. MP3 audio files typically fall between 3 and 10 MB per song. Standard-definition video files for a full movie often reach 700 MB to 1 GB, while full HD video can require 7 to 10 GB or more for the same duration.
File systems and maximum file sizes
File size limits depend on the file system, not just available disk space. FAT32 supports individual files up to 4 GB minus 1 byte. NTFS supports files up to 16 EB minus 1 KB in theory, though practical limits are much lower. exFAT is commonly used for USB drives and supports very large files, making it suitable for 4K video transfers. When planning backups or media archives, verify both total volume capacity and per-file limits before copying data.
Related tools on DozoTools
Working with files often involves more than unit conversion. Use our hash generator for files to verify file integrity with SHA-256 and other algorithms. Reduce image file sizes with the image compressor before uploading. Generate random values for testing with the random number generator.
File Size Calculator FAQs
Why is 1 MB 1024 KB and not 1000 KB?
In computing, file sizes traditionally use binary (base 1024) units because computers work in powers of two. One megabyte in binary equals 1,048,576 bytes (1024 × 1024), which is 1024 kilobytes. Storage manufacturers often use decimal (base 1000) labels, so a "1 TB" drive may show as less in Windows, which still reports binary units.
What is a kibibyte (KiB)?
A kibibyte (KiB) is the IEC binary prefix for 1024 bytes. It was introduced to distinguish binary kilobytes from decimal kilobytes (1000 bytes). One kibibyte equals 1024 bytes, while one decimal kilobyte (kB) equals 1000 bytes. Use KiB when referring to binary storage sizes in operating systems and file managers.
How many bytes are in a megabyte?
In binary (IEC) terms, one mebibyte (MiB) contains 1,048,576 bytes (1024 × 1024). In decimal (SI) terms, one megabyte (MB) contains 1,000,000 bytes (1000 × 1000). Always check whether your context uses binary or decimal standards before converting.
How do you convert bits to bytes?
Divide the number of bits by 8 to get bytes, because one byte contains exactly 8 bits. For example, 64 bits equals 8 bytes. To convert bytes to bits, multiply by 8. Network speeds are often measured in bits per second, while file sizes are usually measured in bytes.
What is the largest file size I can send by email?
Most email providers limit attachments to 10–25 MB, though some allow up to 50 MB. For larger files such as videos or high-resolution photos, use cloud storage services like Google Drive, Dropbox, or OneDrive and share a download link instead of attaching the file directly.
Does this file size calculator store my data?
No. All conversions run entirely in your browser. Your input values are never sent to a server, stored in a database, or shared with third parties. You can use the tool offline after the page loads, and clearing your browser does not affect the calculator unless you saved a share link.
What is the difference between KB and KiB?
KB (kilobyte) typically refers to 1000 bytes in decimal/SI measurement, while KiB (kibibyte) refers to 1024 bytes in binary/IEC measurement. The same distinction applies to MB/MiB, GB/GiB, and TB/TiB. This calculator supports both standards so you can match operating system or manufacturer labeling.