基数変換器
2進数、8進数、10進数、16進数間の変換
結果
おすすめの次のステップ
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使い方
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モバイル対応
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Number Base Converter: Binary, Octal, Decimal, and Hexadecimal Made Easy
Key Takeaways
- Number base conversion is fundamental to programming, networking, and computer science — understanding binary and hex is essential for any developer.
- Hexadecimal is used everywhere in computing: CSS colors (#FF5733), memory addresses, MAC addresses, and error codes.
- Binary is how computers actually store and process all data — converting between bases helps you understand what's happening at the hardware level.
Computers think in binary, networks use hexadecimal, file permissions use octal, and humans prefer decimal. Moving between these number systems is a daily task for developers, network engineers, and computer science students. A number base converter eliminates the error-prone mental math of manual conversion, letting you instantly translate values between binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16).
Every CSS color code is a hexadecimal number — #FFFFFF represents three decimal values: 255, 255, 255
Hex in Action
When to Use a Number Base Converter
Web Development and CSS Colors
Convert between hex color codes (#FF5733) and their RGB decimal values (255, 87, 51) when working with design specifications and color manipulation.
Debugging and Memory Inspection
Memory addresses, error codes, and register values are displayed in hexadecimal. Convert to decimal or binary to understand bit patterns and diagnose issues.
Networking and Subnetting
Subnet masks, IPv6 addresses, and MAC addresses use hexadecimal notation. Binary conversion is essential for understanding network address calculations.
Computer Science Education
Students learning data representation, bitwise operations, and computer architecture need to fluently convert between binary, decimal, and hex.
Tips for Number Base Conversion
Hexadecimal uses 0-9 and A-F, where A=10, B=11, C=12, D=13, E=14, F=15. Each hex digit represents exactly 4 binary bits.
To quickly convert hex to binary, expand each hex digit to its 4-bit binary equivalent: F = 1111, A = 1010, 3 = 0011.
Octal (base 8) is used in Unix/Linux file permissions: 755 means rwxr-xr-x. Each octal digit maps to 3 binary bits.
Prefix conventions: 0x for hex (0xFF), 0b for binary (0b1010), 0o for octal (0o17) in most programming languages.
All calculations are performed locally in your browser. No data is sent to any server, ensuring your work remains private.