File Size Converter

Base Unit

Bytes (B)

Bytes

Decimal Units (Base 1000)

Kilobytes (KB)

Kilobytes

Megabytes (MB)

Megabytes

Gigabytes (GB)

Gigabytes

Terabytes (TB)

Terabytes

Petabytes (PB)

Petabytes

Binary Units (Base 1024)

Kibibytes (KiB)

Kibibytes

Mebibytes (MiB)

Mebibytes

Gibibytes (GiB)

Gibibytes

Tebibytes (TiB)

Tebibytes

Pebibytes (PiB)

Pebibytes

File Size Conversion Reference

System	Unit	Exact bytes	Common use
Decimal (SI)	1 KB	1,000	Files and storage
Decimal (SI)	1 MB	1,000,000	Files and network rates
Decimal (SI)	1 GB	1,000,000,000	Disk capacity
Binary (IEC)	1 KiB	1,024	Memory and system tools
Binary (IEC)	1 MiB	1,048,576	Memory and software
Binary (IEC)	1 GiB	1,073,741,824	Memory capacity

About File Size Converter

Our free online File Size Converter helps you convert between different digital storage units instantly. Whether you're calculating storage requirements, understanding file sizes, or planning data transfers, this tool provides accurate conversions between bytes, KB, MB, GB, TB, and beyond.

Key Features

All Units

Convert between Bytes, KB, MB, GB, TB, and PB.

Real-time Conversion

All units update automatically as you type.

Binary & Decimal

Supports both IEC (1024-based) and SI (1000-based) standards.

100% Client-side

All calculations happen in your browser - your data stays private.

Copy Support

One-click copy for any converted value.

Practical Precision

Shows integers exactly when possible and up to 10 decimal places for everyday conversions.

How to Use

1Enter a file size value in any unit field.
2All other unit fields automatically update with converted values.
3Click the copy icon to copy any value.
4Use 'Clear All' to reset all fields.

Pro Tips

💡KB is the decimal SI unit for 1,000 bytes; KiB is the binary IEC unit for 1,024 bytes.
💡Hard drive manufacturers use decimal (1 TB = 1000 GB).
💡Memory and many system tools use binary units such as MiB and GiB.
💡A 1 TB drive contains about 931 GiB; some operating systems display that binary value with a GB label.

Common Examples

1 GB in decimal units

Input: 1 GB
Output: 1,000 MB · 1,000,000,000 bytes

Drive manufacturers and network speeds normally use base-1000 SI units.

1 GiB in binary units

Input: 1 GiB
Output: 1,024 MiB · 1,073,741,824 bytes

Operating systems and memory calculations commonly use base-1024 IEC units.

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Frequently Asked Questions

Why is my hard drive smaller than advertised?

Drive manufacturers use decimal SI units, so 1 TB is 1,000,000,000,000 bytes. That same byte count is about 931 GiB. Some operating systems display the binary value while labeling it GB, which makes the drive appear smaller even though no capacity is missing.

What's the difference between KB and KiB?

KB (kilobyte) is exactly 1,000 bytes in the SI system. KiB (kibibyte) is exactly 1,024 bytes in the IEC binary system. This converter shows both separately.

How many MB is 1 GB?

By the SI definitions used for KB, MB, and GB, 1 GB is exactly 1,000 MB. In the IEC binary system, 1 GiB is exactly 1,024 MiB.

What comes after Terabyte?

In decimal SI units, 1 petabyte (PB) is 1,000 terabytes (TB). In binary IEC units, 1 pebibyte (PiB) is 1,024 tebibytes (TiB). Exabyte, zettabyte, and yottabyte follow petabyte.