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ASCII value of 'A' and 'a'

ASCII codes for uppercase 'A' (65) and lowercase 'a' (97). Free online tool — no sign-up. Clear formulas and worked examples. Runs locally in your browser.

ASCII letters 'A' and 'a' specification

Version 1.0.0 · Engine tested

Calculation status
  • Engine tested 4 published cases
  • Named expert review Not performed
  • Calculation version 1.0.0

Review policy

Definition
Uppercase 'A' is ASCII 65 (0x41); lowercase 'a' is 97 (0x61). Letter case differs by a fixed offset of 32 within A–Z / a–z.
What it calculates
Documents ASCII / Unicode encodings for uppercase 'A' (65) and lowercase 'a' (97), and the letter ranges A–Z / a–z.
Inputs
  • Reference lookup for letters 'A' and 'a'
Outputs
  • 'A': decimal 65 · hex 0x41 · binary 01000001
  • 'a': decimal 97 · hex 0x61 · binary 01100001
  • Uppercase block 65–90; lowercase block 97–122 (offset +32)
Formula
code('A')=65; code('a')=97; code(lower)=code(upper)+32

Uppercase A and lowercase a are among the most common ASCII letters. Uppercase letters occupy codes 65–90; lowercase letters occupy 97–122 (offset +32 from uppercase).

ASCII codes for 'A'

Property Value
Character A
Decimal code 65
Hex code 41
Binary code 01000001
Octal code 101
Escape sequence \x41
HTML code A

ASCII codes for 'a'

Property Value
Character a
Decimal code 97
Hex code 61
Binary code 01100001
Octal code 141
Escape sequence \x61
HTML code a

How to type

Method 'A' 'a'
Keyboard Shift + A a (no shift)
Windows Alt code Alt+65 Alt+97
C/C++ escape \x41 or \101 \x61 or \141
HTML entity A a
Unicode U+0041 U+0061

FAQ

What is the ASCII value of capital A?

Decimal 65, hexadecimal 0x41.

What is the ASCII value of lowercase a?

Decimal 97, hexadecimal 0x61.

Why is lowercase a exactly 32 more than uppercase A?

ASCII reserves bit 5 (value 32) as the case bit. Toggling it converts between upper and lower case for letters A–Z.

Are A and a the same in Unicode?

They are different code points: U+0041 (A) and U+0061 (a). Unicode includes ASCII as its first 128 code points.

How do I convert a letter to uppercase in code?

In C: toupper('a') → 'A'. In Python: 'a'.upper() → 'A'.

Assumptions
  • Standard ASCII / Unicode Basic Latin letter ranges.
  • Case conversion uses a fixed +32 offset within A–Z / a–z.
  • Reference page; encodings are fixed by the ASCII standard.
Units
  • Dec / Oct: integer
  • Hex: two hex digits
  • Bin: 8-bit string
Boundary conditions
  • Only A–Z (65–90) and a–z (97–122) follow the +32 case rule.
  • Accented letters are outside basic ASCII.
Example
'A' → 65 / 0x41; 'a' → 97 / 0x61
Validation cases
  • 'A' → 65 / 0x41 / 01000001
  • 'a' → 97 / 0x61 / 01100001
  • 'Z' → 90 / 0x5A
  • 'z' → 122 / 0x7A
Sources
  • ANSI X3.4 / ISO/IEC 646 ASCII
  • Unicode Standard (Basic Latin / Latin-1 Supplement where applicable)
Calculation version
1.0.0
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