Number Base Converter
Convert numbers between Binary, Octal, Decimal, and Hexadecimal bases
Result: -
All Conversions
| Binary: | - |
| Octal: | - |
| Decimal: | - |
| Hexadecimal: | - |
Quick Reference Table
| Decimal | Binary | Octal | Hexadecimal |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 1 | 1 | 1 | 1 |
| 2 | 10 | 2 | 2 |
| 3 | 11 | 3 | 3 |
| 4 | 100 | 4 | 4 |
| 5 | 101 | 5 | 5 |
| 6 | 110 | 6 | 6 |
| 7 | 111 | 7 | 7 |
| 8 | 1000 | 10 | 8 |
| 9 | 1001 | 11 | 9 |
| 10 | 1010 | 12 | A |
| 11 | 1011 | 13 | B |
| 12 | 1100 | 14 | C |
| 13 | 1101 | 15 | D |
| 14 | 1110 | 16 | E |
| 15 | 1111 | 17 | F |
This guide explains how to convert octal numbers to decimal. We use clear steps and plain language.
What Is Octal?
Octal is a base-8 number system. It uses only the digits 0 through 7. Each digit has a weight based on its position.
What Is Decimal?
Decimal is the common system with ten digits (0 to 9). We use it every day for counting and calculations.
The Conversion Method: From Octal to Decimal
Each digit in an octal number has a place value. The rightmost digit multiplies by 1, the next by 8, then 64, and so on.
For example, with octal 345:
- 5 × 1 = 5
- 4 × 8 = 32
- 3 × 64 = 192
Add the results to get 229. So, 345 in octal is 229 in decimal.
Example Conversion
Convert octal 7014 to decimal:
- Break the digits:
- 4 (rightmost) × 1 = 4
- 1 × 8 = 8
- 0 × 64 = 0
- 7 × 512 = 3584
- Add them: 4 + 8 + 0 + 3584 = 3596
Thus, 7014 in octal equals 3596 in decimal.
How to Use This Tool
The tool converts numbers among binary, octal, decimal, and hexadecimal.
Follow these steps:
- Select the base for your input using the “From:” dropdown. For octal, choose the option labeled Octal (Base 8).
- Enter your number in the input field. Use digits 0 to 7 for octal.
- Choose your target base in the “To:” dropdown. For decimal, select Decimal (Base 10).
- Watch as the tool displays the converted number in the result area.
The tool also shows all conversions for binary, octal, decimal, and hexadecimal in a table.
Input Field Explained
The “From:” field tells the tool what kind of number you have. It adjusts the input placeholder to guide you.
The “To:” field sets the base you want to convert to.
The result section shows your conversion immediately.
Output and Interpretation
The output shows the converted value. It also fills in a table with numbers in each base.
If the input is invalid, an error message appears in red.
Limitations and Notes
The tool does not convert fractions. It works with whole numbers only. It may not handle very large numbers.
Use it for Unix file permissions, computer class exercises, or quick conversions.
Quick Reference Table
| Octal | Decimal |
|---|---|
| 0 | 0 |
| 7 | 7 |
| 10 | 8 |
| 20 | 16 |
| 77 | 63 |
This table gives common octal and decimal pairs to check your work.
Alternate Calculation Method
You can also calculate manually from left to right:
- Start at zero.
- For each digit, multiply your total by eight.
- Add the current digit to the total.
This method works best for quick mental calculations and reinforces the base conversion concept.