Octal (base 8)
Octal (base 8) uses the digits 0 through 7. Each octal digit represents exactly three bits, which is why octal was widely used on early minicomputers and is still the conventional notation for Unix file-permission masks (e.g. 755).
Octal to Hexadecimal Converter
755 (oct) = 1ED (hex)
Convert octal numbers to hexadecimal numbers exactly, for any size. Convertitive parses your input as a BigInt — so 64-bit values, 256-bit hex strings, and even larger numbers round-trip without rounding. For quick reference: 755 oct = 1ED hex, and 100 oct = 40 hex.
Quick
How to convert octal numbers to hexadecimal numbers
Enter a value
Type a octal integer in the From field. Allowed characters: 0 through 7.
Read the hexadecimal result
The To field updates as you type. For example, the octal value 755 equals 1ED in hexadecimal.
Copy or share
Use the copy button to grab the result. You can change either base from its dropdown without leaving the page.
Reference table
Fifty representative values. Every row is computed exactly by the same BigInt-based converter that powers the widget above.
| Octal (oct) | Hexadecimal (hex) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 6 | 6 |
| 7 | 7 |
| 10 | 8 |
| 11 | 9 |
| 12 | A |
| 13 | B |
| 14 | C |
| 15 | D |
| 16 | E |
| 17 | F |
| 20 | 10 |
| 21 | 11 |
| 22 | 12 |
| 23 | 13 |
| 24 | 14 |
| 30 | 18 |
| 37 | 1F |
| 40 | 20 |
| 44 | 24 |
| 52 | 2A |
| 60 | 30 |
| 62 | 32 |
| 77 | 3F |
| 100 | 40 |
| 144 | 64 |
| 177 | 7F |
| 200 | 80 |
| 310 | C8 |
| 377 | FF |
| 400 | 100 |
| 764 | 1F4 |
| 777 | 1FF |
| 1000 | 200 |
| 1750 | 3E8 |
| 1777 | 3FF |
| 2000 | 400 |
| 4000 | 800 |
| 10000 | 1000 |
| 20000 | 2000 |
| 40000 | 4000 |
| 100000 | 8000 |
| 177777 | FFFF |
| 200000 | 10000 |
| 4000000 | 100000 |
Frequently asked questions
- How do I convert octal numbers to hexadecimal numbers?
- Enter your octal value above. Convertitive parses it as an arbitrary-precision integer and reformats it in hexadecimal. The conversion is exact for any size — there's no float rounding.
- What is 755 in hexadecimal?
- 755 (octal) equals 1ED in hexadecimal.
- Are negative numbers supported?
- No, only non-negative integers are supported for octal ↔ hexadecimal. Two's-complement encodings depend on a chosen bit-width, which this tool does not assume.
- What's the largest number I can convert?
- Any size. Convertitive uses JavaScript BigInt, which has no fixed upper bound — 256-bit hex strings, 512-bit and bigger all round-trip exactly.
- How many bits does the result take?
- An n-digit number in base 8 needs roughly 3.00 × n bits to store. The exact bit length equals ⌈log₂(value + 1)⌉.
- Is hex case-sensitive?
- No. You can type hex with letters in either case. Output is always uppercase (A–F).
- Are conversion factors exact?
- Yes. Base conversion is integer-to-integer; there are no factors, no rounding, no precision loss.
- Why would I convert octal numbers to hexadecimal numbers?
- Hex is the standard compact notation for binary data — memory addresses, color codes, hashes. Converting from octal to hex packs the same value into a more readable form.
About octal and hexadecimal
Hexadecimal (base 16)
Hexadecimal (base 16) uses digits 0–9 plus the letters A–F to encode the values 10–15. It is the dominant compact notation for binary data: every two hex digits represent exactly one byte. Used universally for memory addresses, color codes (#RRGGBB), and cryptographic hashes.