Decimal to Fraction Calculator

Decimal Fraction to Octal

Enter a decimal fraction below to instantly convert it to its octal representation with a detailed step-by-step breakdown.

Visual Representation

Base-10 → Base-8 digits
Enter a number…
Value as proportion of 1
0%

How Decimal to Octal Conversion Works

Live Conversion Demo

1
Enter Decimal
2
Conversion Steps
0.625 × 1000 = 625
625 / 1000
GCD(625, 1000) = 125
625÷125 / 1000÷125
3
Result
5/8
62.5%
Pie Chart
Proportion
0 5/8 1
01

Enter Your Decimal

Type any decimal number into the calculator. Supports standard decimals, repeating patterns, and measurement values.

02

Instant Conversion

Our algorithm converts your decimal to a fraction instantly, finding the greatest common divisor to simplify it to the lowest terms.

03

Get Results with Steps

See your fraction in simplified form, as a mixed number, and with a complete step-by-step breakdown of the conversion process.

How to Convert Decimal Fractions to Octal

To convert a decimal number with a fractional part to octal, you split the number into its integer and fractional parts and convert them separately.

Steps

  1. Separate the number into the integer part and the fractional part.
  2. Convert the integer part to octal by repeatedly dividing by 8 and recording the remainders.
  3. Convert the fractional part to octal by repeatedly multiplying by 8 and recording the integer part of the result.
  4. Combine the two octal parts with a decimal point.

Example

Convert 56.75 to octal:
1. Integer part (56): 56 ÷ 8 = 7 rem 0, 7 ÷ 8 = 0 rem 7 → 70
2. Fractional part (0.75): 0.75 × 8 = 6.0 (int 6) → .6
3. Combine: 70 + .6 = 70.6₈

Common Conversions

Decimal Octal
0.1250.1
0.250.2
0.50.4
0.750.6
1.51.4

Frequently Asked Questions

Common questions about octal system, base-8, Unix permissions, legacy computing

01 What is the octal numeral system?

Octal, or base-8, is a numbering system that uses digits from 0 to 7. Historically, it was widely used in computing because 8 is a power of 2.

02 How is octal used in Unix file permissions?

Unix and Linux systems use 3-digit octal numbers to set file permissions (e.g., 755). Each digit represents read (4), write (2), and execute (1) access for the user, group, and others.

03 Why is octal less common today than hexadecimal?

Modern computer architectures are usually based on 16, 32, or 64 bits, which are more easily represented by base-16 (hex). Octal was more common with early 12-bit, 24-bit, or 36-bit systems.

04 How does base-8 relate to binary?

Every octal digit represents exactly 3 bits of binary data. For example, the octal digit 7 corresponds to the binary sequence 111.

05 Can decimal fractions easily be represented in octal?

Just like with binary and hex, some decimal fractions terminate cleanly in octal, while others (like 0.5) result in a repeating sequence depending on their relationship with powers of 8.

|