Octal to Hexadecimal Converter
Convert octal numbers to hexadecimal format
Tip: Enter an octal number (0-7 only). The conversion happens in real-time.
Runs in your browserOctal Hex
Octal to hex, step by step
Convert octal to hexadecimal
Type an octal number and the hex result appears as you type, in capital letters. Results longer than four digits are also split into byte pairs, and the window bar shows the bit length.
Octal digits are three bits and hex digits four, so no octal digit has a matching hex digit. The conversion goes through binary: the bits stay the same, only the way they are grouped changes.
How to convert octal to hex by hand
Write each octal digit as three bits, regroup the bits in fours from the right, and write each group as a hex digit. For 755:
| Stage | Result |
|---|---|
| Octal digits | 7 5 5 |
| Three bits each | 111 101 101 |
| Regrouped in fours from the right | 0001 1110 1101 |
| Hex digits | 1 E D |
So 755 in octal is 1ED in hex. Both are 493 in decimal, which is a quick way to check the answer.
Octal to hex table
| Octal | Hex |
|---|---|
| 7 | 7 |
| 10 | 8 |
| 17 | F |
| 20 | 10 |
| 37 | 1F |
| 77 | 3F |
| 100 | 40 |
| 177 | 7F |
| 200 | 80 |
| 377 | FF |
| 644 | 1A4 |
| 755 | 1ED |
| 777 | 1FF |
| 177777 | FFFF |
377 and FF are the pair you meet most: both are 255, the largest value of one byte. Permissions such as 644 turn into 1A4 in hex, which shows why they are kept in octal: the hex form hides the three user classes.
Converting hex to octal instead?
The hex to octal converter writes each hex digit as four bits and regroups them in threes.
For the decimal value, use the octal to decimal converter; the number system converter shows all four bases at once.
Octal to hex questions
FF. 377 is 11 111 111 in binary; regrouped as 1111 1111 that is F and F.
An octal digit is three bits and a hex digit four, so their boundaries only meet every 12 bits: every four octal digits or three hex digits.
No. You get the digits in capitals, such as 1ED. Add 0x yourself if your code needs it.
Yes. 0o755 and 755 both give 1ED, and spaces and underscores are skipped too.
No. The conversion runs in your browser.