Convert a whole number from hexadecimal (base 16) to octal (base 8), preserving its exact integer value.
Use hexadecimal digits 0–9 and A–F. Letter case does not change the value.
Up to 1,000 hexadecimal digits are accepted. Input is case-insensitive; output is uppercase-normalized hexadecimal and minimal octal notation.
The Hex to Octal Calculator helps you rewrite a hexadecimal whole number in base eight. Hex and octal are two compact ways to display binary-aligned values. The converter is handy for permissions, legacy system values and checking base-conversion exercises.
Use it as a transparent arithmetic check. The worked example below follows the same inputs and rounding as the live form, while the notes explain what the result can and cannot support.
The converter uses direct digit grouping rather than a floating-point base conversion, preserving large integer values exactly.
First evaluate H = Σ di16i. Write that same integer as O = Σ oj8j. The binary shortcut works because 16 = 24 and 8 = 23.
| Input or result | Meaning |
|---|---|
| Hex input | The source whole number in base 16. |
| Octal output | The identical value in base 8, using digits 0 through 7. |
| Bit grouping | Four bits per hex digit and three bits per octal digit. |
| Range | Up to 1,000 entered hex digits; direct grouping preserves the exact integer. |
For FF, hex-to-binary gives 11111111. Grouping from the right in threes gives 011 111 111. Those groups equal 3, 7 and 7, so the octal result is 377.
Decimal checking reaches the same answer: 3×64 + 7×8 + 7 = 192 + 56 + 7 = 255.
Octal 377 and hexadecimal FF are different spellings of the same integer. Neither form says whether the value is a file permission, an address or plain arithmetic. In a fixed-width record, store the width separately because the converter returns the shortest ordinary numeral.
The conversion is exact for inputs up to 1,000 hex digits. It does not convert negative, fractional or encoded text values, and does not assign application-specific meaning to the number.
Do a quick reasonableness check after calculating. A correct-looking decimal can still answer the wrong question when the source hexadecimal whole number uses a different definition.
It converts a nonnegative hexadecimal integer to its equivalent octal representation, using digits 0 through 7.
Use 0–9 and A–F. Lowercase a–f is also accepted. Prefixes such as 0x, signs, separators, and decimal points are not accepted.
A correct base conversion is unique for the same nonnegative integer. Check that the other tool accepts the same digits and that you are comparing octal output rather than a decimal or prefixed representation.
No. Hexadecimal and octal integer representations are exact. Leading zeroes may be omitted, but the represented value is unchanged.
Up to 1,000 hexadecimal digits. Each digit is converted to four bits and the bits are regrouped in threes, preserving the integer exactly.
Convert FF to binary as 11111111, group from the right as 011 111 111, and map those groups to 377. Both FF₁₆ and 377₈ equal decimal 255.
No. Leading zeroes are omitted because they do not change the integer value. Preserve the width separately if the number belongs to a fixed-width field.