Char to ASCII Converter

Computer Science & The ASCII Character Encoding Standard (ANSI X3.4)

The American Standard Code for Information Interchange (ASCII) was standardized in 1963 to encode text on digital computers:

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• Standard 7-Bit ASCII Code Ranges (0--127)**:

• Control Codes (0--31 & 127): NUL (0), LF (10), CR (13), ESC (27), DEL (127).

• Printable Characters (32--126):

• Space: 32

• Digits '0'–'9': 48--57 (0x30–0x39)

• Uppercase 'A'–'Z': 65--90 (0x41–0x5A)

• Lowercase 'a'–'z': 97--122 (0x61–0x7A)

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• The Case Bit-Flip Principle**:

'a' - 'A' = 97 - 65 = 32 = 2^5 (Bit 5 is toggled)

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• Representation Formats**:

Dec: 65 Hex: 0x41 Bin: 01000001_2 Oct: 0o101 HTML: \&\#65;

How to Use This Calculator

Enter your Character or Text String (e.g. A or Hello) and ASCII Encoding Benchmark — choose from Custom Character / String, Uppercase 'A' (Dec: 65 / Hex: 0x41 / Bin: 01000001), Lowercase 'a' (Dec: 97 / Hex: 0x61 / Bin: 01100001). Results update instantly as you type — adjust any value to compare scenarios.

The Formula

Formula Reference: Char to ASCII Converter

Input variables:

characterInputString — Character or Text String

Computed outputs:

decimalAsciiCode — Decimal ASCII Code (Base-10)

hexadecimalAsciiCode — Hexadecimal ASCII Code (Base-16)

binaryEightBitByte — Binary 8-Bit Byte (Base-2)

octalAsciiCode — Octal Code (Base-8)

htmlEntityCode — HTML Numeric Entity

Standard: NIST Handbook 44 and BIPM SI unit definitions

Worked Example

A programmer inspecting the ASCII code for lowercase 'a' verifies that subtracting 32 yields uppercase 'A', which is the universal bit-flip case toggle (01100001_2 vs 01000001_2).

Understanding Your Result

Unit conversion precision: round to the same number of significant figures as your original measurement. Converting 6 feet to meters gives 1.8288 m — but if your measurement was approximate (±1 inch), expressing more than 2 decimal places is false precision. For international trade and technical specifications, SI units (meters, kilograms, liters) are the standard. US customary units (feet, pounds, gallons) differ from Imperial UK units: 1 US gallon = 3.785 L vs. 1 UK gallon = 4.546 L.