Bytes Converter - KB, MB, GB, TB (Binary & Decimal)
Convert bytes to kilobytes, megabytes, gigabytes, terabytes, and petabytes instantly. This storage size calculator supports both binary (1024) and decimal (1000) modes for accurate data size conversion.
Understand the difference between 1024 vs 1000 bytes, and see exactly how many bytes are in 1 GB. Perfect for calculating file sizes, storage capacity, and understanding why your 1 TB drive shows as 931 GB.
Used by developers, sysadmins, and IT professionals.
000000Binary vs Decimal
Binary (1024)
Used by operating systems and programming.
1 KB = 1,024 bytes
Decimal (1000)
Used by storage manufacturers and networking.
1 KB = 1,000 bytes
How to Use
Enter a value in the input field
Select the unit (B, KB, MB, GB, TB, PB)
Choose binary (1024) or decimal (1000)
See instant conversions to all units
Click a preset for common values
Binary vs Decimal
Binary: Used by operating systems and memory. 1 KB = 1,024 bytes.
Decimal: Used by storage manufacturers. 1 KB = 1,000 bytes.
Why It Matters
When you buy a 1 TB hard drive, the manufacturer uses decimal (1,000,000,000,000 bytes), but your OS shows binary (931 GB). This isn't false advertising, just different measurement systems.
Common Reference Sizes
Why Your 1 TB Disk Shows as 931 GB
This is one of the most common questions in computing. When you buy a 1 TB hard drive, the manufacturer measures capacity in decimal: 1 TB = 1,000,000,000,000 bytes (1 trillion bytes).
However, Windows and most operating systems display storage in binary. When you convert those same 1 trillion bytes to binary gigabytes (dividing by 1024³), you get approximately 931 GB.
The math: 1,000,000,000,000 ÷ 1,073,741,824 = 931.32 GB. This isn't false advertising - it's just two different but valid measurement systems.
Frequently Asked Questions
How many bytes are in 1 GB?
In binary: 1 GB = 1,073,741,824 bytes (1024³). In decimal: 1 GB = 1,000,000,000 bytes (1000³). Operating systems use binary; storage manufacturers use decimal.
Which unit does Windows use?
Windows uses binary (1024-based) for displaying file and storage sizes. macOS switched to decimal in 2009. Linux typically uses binary but can be configured either way.
What is the difference between binary and decimal bytes?
Binary uses powers of 1024 (2¹⁰) - used by RAM, file systems, and operating systems. Decimal uses powers of 1000 (10³) - used by hard drive manufacturers and network speeds.
All calculations happen locally in your browser. No data sent to servers.
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