Last updated on July 7th, 2025
In computer science and digital electronics, numbers are often represented in different base systems such as binary, octal, decimal, and hexadecimal. Octal is a base-8 number system that uses digits from 0 to 7. Hexadecimal, on the other hand, is a base-16 number system that uses digits from 0 to 9 and letters from A to F. Sometimes, it's necessary to convert numbers from octal to hexadecimal for various applications. In this topic, we will learn how to convert octal numbers to hexadecimal.
An octal number system is a base-8 numeral system that uses only eight digits: 0 through 7. It is often used in computing since it is easier to convert to binary. Each octal digit represents three binary digits (bits).
Octal numbers are commonly used in digital systems to represent data and instructions.
The hexadecimal number system is a base-16 numeral system. It uses sixteen distinct symbols: 0-9 to represent values zero to nine, and A-F (or a-f) to represent values ten to fifteen.
Hexadecimal is widely used in computing as a more human-friendly representation of binary-coded values.
To convert octal to hexadecimal, follow these steps:
1. Convert the octal number to a binary number.
2. Group the binary digits in sets of four, starting from the right (add leading zeros if necessary).
3. Convert each 4-bit binary group to its hexadecimal equivalent.
Converting octal numbers to hexadecimal involves a two-step process. First, convert the octal number to binary, then convert the binary number to hexadecimal.
Steps to convert octal to hexadecimal:
1. Write down the octal number.
2. Convert each octal digit to a 3-bit binary equivalent.
3. Combine all binary groups into a single binary number.
4. Group binary digits into sets of four (add leading zeros if necessary).
5. Convert each 4-bit binary group to its hexadecimal equivalent.
When working with digital systems, you may encounter the need to convert between different number systems like octal and hexadecimal. Here's a simple chart that shows some common octal-to-hexadecimal conversions for reference.
When converting octal to hexadecimal, people often make mistakes. Here are some common errors to be aware of and tips on how to avoid them.
Convert octal 527 to hexadecimal
Octal 527 = Hexadecimal 157
Convert octal 527 to binary: 5 = 101, 2 = 010, 7 = 111.
Combine to get 101010111.
Group into four: 0001 0101 0111.
Convert each group to hexadecimal: 1, 5, 7.
Therefore, 527 in octal is 157 in hexadecimal.
Convert octal 173 to hexadecimal.
Solution: Converting octal 173 to hexadecimal gives us 7B.
Convert octal 173 to binary: 1 = 001, 7 = 111, 3 = 011.
Combine to get 001111011. Group into four: 0001 1110 11.
Convert each group to hexadecimal: 7, B.
Therefore, 173 in octal is 7B in hexadecimal.
A memory address is given as octal 745. What is the address in hexadecimal?
The address in hexadecimal is 1E5.
Convert octal 745 to binary: 7 = 111, 4 = 100, 5 = 101.
Combine to get 111100101. Group into four: 0001 1110 0101.
Convert each group to hexadecimal: 1, E, 5. Therefore, 745 in octal is 1E5 in hexadecimal.
The code is written as octal 356. What is its code in hexadecimal?
The code in hexadecimal is EE.
Convert octal 356 to binary: 3 = 011, 5 = 101, 6 = 110.
Combine to get 011101110. Group into four: 0011 1011 10. Convert each group to hexadecimal: E, E.
Therefore, 356 in octal is EE in hexadecimal.
Converting octal 641 to hexadecimal
Octal 641 = Hexadecimal 1A1
Convert octal 641 to binary: 6 = 110, 4 = 100, 1 = 001. Combine to get 110100001.
Group into four: 0001 1010 0001.
Convert each group to hexadecimal: 1, A, 1. Therefore, 641 in octal is 1A1 in hexadecimal.
Seyed Ali Fathima S a math expert with nearly 5 years of experience as a math teacher. From an engineer to a math teacher, shows her passion for math and teaching. She is a calculator queen, who loves tables and she turns tables to puzzles and songs.
: She has songs for each table which helps her to remember the tables