Decimal to Octal Converter

Convert decimal numbers to octal instantly. Transform base-10 numbers into base-8 for Unix permissions and legacy system compatibility.

Unix Permission Reference

Each digit = read(4) + write(2) + execute(1)

  • 7 = rwx (full access)
  • 6 = rw- (read + write)
  • 5 = r-x (read + execute)
  • 4 = r-- (read only)
  • 0 = --- (no access)

How to Use

  1. Enter a decimal number
  2. Octal equivalent appears instantly
  3. Use for permissions or programming
  4. Copy the octal result

Features

  • Instant decimal to octal conversion
  • Unix permission helper
  • Shows division steps
  • Handles large numbers
  • Real-time conversion
  • Validates output

About This Tool


Decimal to octal conversion transforms base-10 numbers into the base-8 octal system. This is primarily used today for Unix/Linux file permissions.

The conversion uses repeated division by 8. Divide the decimal by 8, record the remainder (0-7), repeat until the quotient is 0. Read remainders in reverse order.

For example, decimal 493: 493÷8=61 R5, 61÷8=7 R5, 7÷8=0 R7. Remainders 7, 5, 5 give octal 755 (the common permission setting).

Our converter helps system administrators quickly calculate permission values. Each digit represents a permission set: 7=rwx (full), 6=rw- (read+write), 5=r-x (read+execute), 4=r-- (read only).

Understanding decimal to octal conversion is valuable for anyone managing Unix/Linux systems or working with systems that use octal notation.

Frequently Asked Questions

What permission is decimal 493?
Decimal 493 = octal 755, meaning owner has rwx (7), group has r-x (5), others have r-x (5).
How do I calculate permissions?
Add values: read=4, write=2, execute=1. Full access = 4+2+1 = 7. Read-only = 4. Read+execute = 5.
What's the highest single-digit octal?
Octal digits go 0-7. The digit 8 doesn't exist in octal; it would be 10 in octal (8 in decimal).
Why does chmod use octal?
Each permission group (rwx) uses exactly 3 bits, which maps perfectly to one octal digit.
Can I convert negative numbers?
The tool converts positive integers. Negative numbers would need special signed representation.

Convert decimal numbers to octal instantly. Transform base-10 numbers into base-8 for Unix permissions and legacy system compatibility.

Key Features

  • Instant decimal to octal conversion
  • Unix permission helper
  • Shows division steps
  • Handles large numbers
  • Real-time conversion
  • Validates output

How to Use This Tool

  1. Enter a decimal number
  2. Octal equivalent appears instantly
  3. Use for permissions or programming
  4. Copy the octal result
Decimal to octal conversion transforms base-10 numbers into the base-8 octal system. This is primarily used today for Unix/Linux file permissions. The conversion uses repeated division by 8. Divide the decimal by 8, record the remainder (0-7), repeat until the quotient is 0. Read remainders in reverse order. For example, decimal 493: 493÷8=61 R5, 61÷8=7 R5, 7÷8=0 R7. Remainders 7, 5, 5 give octal 755 (the common permission setting). Our converter helps system administrators quickly calculate permission values. Each digit represents a permission set: 7=rwx (full), 6=rw- (read+write), 5=r-x (read+execute), 4=r-- (read only). Understanding decimal to octal conversion is valuable for anyone managing Unix/Linux systems or working with systems that use octal notation.

Benefits

  • Set Unix file permissions
  • Work with legacy systems
  • Programming education
  • Number system learning

Frequently Asked Questions

What permission is decimal 493?

Decimal 493 = octal 755, meaning owner has rwx (7), group has r-x (5), others have r-x (5).

How do I calculate permissions?

Add values: read=4, write=2, execute=1. Full access = 4+2+1 = 7. Read-only = 4. Read+execute = 5.

What's the highest single-digit octal?

Octal digits go 0-7. The digit 8 doesn't exist in octal; it would be 10 in octal (8 in decimal).

Why does chmod use octal?

Each permission group (rwx) uses exactly 3 bits, which maps perfectly to one octal digit.

Can I convert negative numbers?

The tool converts positive integers. Negative numbers would need special signed representation.

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