Octal to Decimal Converter
Easily convert octal numbers to their decimal equivalent.
Octal Input
Decimal Output
Why Use This Tool? ✅
Fast & Accurate
Converts octal to decimal instantly and precisely as you type.
Supports All Octal Inputs
Correctly converts both short and very long octal strings into decimal values.
User-Friendly Interface
A simple, clean two-panel layout makes converting from octal to decimal effortless.
Perfect for Learning
An essential tool for students and developers learning about computer number systems.
From Base-8 to Base-10: Understanding Octal 🔢
The octal (base-8) number system was historically important in computing as a compact representation of binary numbers. While less common today than hexadecimal, understanding how to convert octal to the familiar decimal (base-10) system is a key skill in computer science and digital electronics.
How to Convert from Octal to Decimal
Converting an octal number to decimal involves understanding place values, which are powers of 8. Starting from the rightmost digit, each position represents 8 to the power of 0, 1, 2, 3, and so on.
Let's convert the octal number `755`:
- Write down the octal number:
7 5 5 - Assign place values to each digit, from right to left:
- 5 * (8⁰) = 5 * 1 = 5
- 5 * (8¹) = 5 * 8 = 40
- 7 * (8²) = 7 * 64 = 448
- Add up the results:
5 + 40 + 448 = 493
So, the octal number 755 is equal to the decimal number 493. This converter performs this calculation instantly for any valid octal string.
Where is Octal Used?
While hexadecimal has largely replaced it, octal is still found in some computing contexts, most famously in the file permission system for Unix and Linux. The `chmod` command uses octal digits to represent read, write, and execute permissions for different user groups. Understanding this conversion helps demystify how these fundamental system commands work.