Master Converter Tool
Octal to Decimal Converter
Convert Octal (base-8) values to Decimal (base-10) numbers.
Tool Key Features
Instant Conversion
Sub-millisecond base-2 to base-10 calculation.
Accurate Results
Guaranteed 100% mathematical precision.
Unlimited Usage
Convert as many values as you need for free.
Mobile Friendly
Fully responsive UI on phone, tablet, & desktop.
Copy Result
One-click copy output to clipboard.
Secure Processing
All processing happens locally in your browser.
Free Forever
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What is Octal to Decimal Converter?
Octal to Decimal conversion transforms base-8 octal values into standard decimal numbers.
How to Use the Octal to Decimal Converter
- Enter octal value (0-7 digits).
- Click Convert.
Live Conversion Examples
Input: 77Output: 63
(7×8¹) + (7×8⁰) = 56 + 7 = 63
How the Conversion Works
Binary conversion relies on positional values of powers of 2. Each bit position starting from the right (index 0) has a weight of 2^n:
2^7
128
2^6
64
2^5
32
2^4
16
2^3
8
2^2
4
2^1
2
2^0
1
Conversion Formula
Decimal = Σ (bit_i × 2^i) where i is the bit index from right to left.
Binary to Decimal Conversion Table (0–32)
| Decimal | Binary (8-bit) | Hexadecimal |
|---|---|---|
| 0 | 00000000 | 0x00 |
| 1 | 00000001 | 0x01 |
| 2 | 00000010 | 0x02 |
| 3 | 00000011 | 0x03 |
| 4 | 00000100 | 0x04 |
| 5 | 00000101 | 0x05 |
| 6 | 00000110 | 0x06 |
| 7 | 00000111 | 0x07 |
| 8 | 00001000 | 0x08 |
| 9 | 00001001 | 0x09 |
| 10 | 00001010 | 0x0A |
| 11 | 00001011 | 0x0B |
| 12 | 00001100 | 0x0C |
| 13 | 00001101 | 0x0D |
| 14 | 00001110 | 0x0E |
| 15 | 00001111 | 0x0F |
| 16 | 00010000 | 0x10 |
| 17 | 00010001 | 0x11 |
| 18 | 00010010 | 0x12 |
| 19 | 00010011 | 0x13 |
| 20 | 00010100 | 0x14 |
| 21 | 00010101 | 0x15 |
| 22 | 00010110 | 0x16 |
| 23 | 00010111 | 0x17 |
| 24 | 00011000 | 0x18 |
| 25 | 00011001 | 0x19 |
| 26 | 00011010 | 0x1A |
| 27 | 00011011 | 0x1B |
| 28 | 00011100 | 0x1C |
| 29 | 00011101 | 0x1D |
| 30 | 00011110 | 0x1E |
| 31 | 00011111 | 0x1F |
| 32 | 00100000 | 0x20 |
Frequently Asked Questions
What digits are allowed in octal?
Octal allows digits 0, 1, 2, 3, 4, 5, 6, 7.