Last updated on August 19th, 2025
253 in binary is written as 11111101 because the binary system uses only two digits, 0 and 1, to represent numbers. This number system is widely used in computer systems. In this topic, we are going to learn about converting 253 into a binary system.
The process of converting 253 from decimal to binary involves dividing the number 253 by 2. Here, it is divided by 2 because the binary number system uses only 2 digits (0 and 1). The quotient becomes the dividend in the next step, and the process continues until the quotient becomes 0.
This method is commonly used to convert 253 to binary. In the last step, the remainder is noted down bottom side up, and that becomes the converted value.
For example, the remainders noted down after dividing 253 by 2 until getting 0 as the quotient form the binary number 11111101. Remember, the remainders here have been written upside down.
In the table shown below, the first column shows the binary digits (1 and 0) representing 253. The second column represents the place values of each digit, and the third column is the value calculation, where the binary digits are multiplied by their corresponding place values.
The results of the third column can be added to cross-check if 11111101 in binary is indeed 253 in the decimal number system.
253 can be converted easily from decimal to binary. The methods mentioned below will help us convert the number. Let’s see how it is done.
Expansion Method: Let us see the step-by-step process of converting 253 using the expansion method.
Step 1 - Figure out the place values: In the binary system, each place value is a power of 2. Therefore, in the first step, we will ascertain the powers of 2. 2^0 = 1 2^1 = 2 2^2 = 4 2^3 = 8 2^4 = 16 2^5 = 32 2^6 = 64 2^7 = 128 2^8 = 256 Since 256 is greater than 253, we stop at 2^7 = 128.
Step 2 - Identify the largest power of 2: In the previous step, we stopped at 2^7 = 128. This is because in this step, we have to identify the largest power of 2, which is less than or equal to the given number, 253. Since 2^7 is the number we are looking for, write 1 in the 2^7 place. Now the value of 2^7, which is 128, is subtracted from 253. 253 - 128 = 125.
Step 3 - Identify the next largest power of 2: In this step, we need to find the largest power of 2 that fits into the result of the previous step, 125. So, the next largest power of 2 is 2^6 = 64. Now, we have to write 1 in the 2^6 place. And then subtract 64 from 125. 125 - 64 = 61. Continue this process for each step: 2^5 = 32: 61 - 32 = 29. 2^4 = 16: 29 - 16 = 13. 2^3 = 8: 13 - 8 = 5. 2^2 = 4: 5 - 4 = 1. 2^0 = 1: 1 - 1 = 0.
Step 4 - Identify the unused place values: Write 1s in the used places and 0s in unused places. Now, by substituting the values, we get: 1 in the 2^0 place 0 in the 2^1 place 1 in the 2^2 place 1 in the 2^3 place 1 in the 2^4 place 1 in the 2^5 place 1 in the 2^6 place 1 in the 2^7 place
Step 5 - Write the values in reverse order: We now write the numbers upside down to represent 253 in binary. Therefore, 11111101 is 253 in binary.
Grouping Method: In this method, we divide the number 253 by 2. Let us see the step-by-step conversion.
Step 1 - Divide the given number 253 by 2. 253 / 2 = 126. Here, 126 is the quotient and 1 is the remainder.
Step 2 - Divide the previous quotient (126) by 2. 126 / 2 = 63. Here, the quotient is 63 and the remainder is 0.
Step 3 - Repeat the previous step. 63 / 2 = 31. Now, the quotient is 31, and 1 is the remainder.
Step 4 - Repeat the previous step. 31 / 2 = 15. The quotient is 15 and the remainder is 1. 15 / 2 = 7. The quotient is 7 and the remainder is 1. 7 / 2 = 3. The quotient is 3 and the remainder is 1. 3 / 2 = 1. The quotient is 1 and the remainder is 1. 1 / 2 = 0. Here, the remainder is 1. And we stop the division here because the quotient is 0.
Step 5 - Write down the remainders from bottom to top. Therefore, 253 (decimal) = 11111101 (binary).
There are certain rules to follow when converting any number to binary. Some of them are mentioned below:
This is one of the most commonly used rules to convert any number to binary. The place value method is the same as the expansion method, where we need to find the largest power of 2. Let’s see a brief step-by-step explanation to understand the first rule. Find the largest power of 2 less than or equal to 253. Since the answer is 2^7, write 1 next to this power of 2. Subtract the value (128) from 253. So, 253 - 128 = 125. Find the largest power of 2 less than or equal to 125. The answer is 2^6. So, write 1 next to this power. Continue the process until the remainder is 0. Final conversion will be 11111101.
The division by 2 method is the same as the grouping method. A brief step-by-step explanation is given below for better understanding. First, 253 is divided by 2 to get 126 as the quotient and 1 as the remainder. Now, 126 is divided by 2. Here, we will get 63 as the quotient and 0 as the remainder. Continue dividing the quotient until we get a quotient of 0. Write the remainders upside down to get the binary equivalent of 253, 11111101.
This rule also involves breaking the number into powers of 2. Identify the powers of 2 and write them down in decreasing order i.e., 2^7, 2^6, 2^5, 2^4, 2^3, 2^2, 2^1, and 2^0. Find the largest power that fits into 253. Repeat the process and allocate 1s and 0s to the suitable powers of 2. Combine the digits (0 and 1) to get the binary result.
The limitation of the binary system is that only 0s and 1s can be used to represent numbers. The system doesn’t use any other digits other than 0 and 1. This is a base 2 number system, where the binary places represent powers of 2. So, every digit is either a 0 or a 1. To convert 253, we use 0s and 1s according to the powers of 2.
Learning a few tips and tricks is a great way to solve any mathematical problems easily. Let us take a look at some tips and tricks for binary numbers up to 253.
Memorize to speed up conversions: We can memorize the binary forms for numbers up to certain limits for quick reference. Recognize the patterns: There is a peculiar pattern when converting numbers from decimal to binary.
Even and odd rule: Whenever a number is even, its binary form will end in 0. For e.g., 254 is even and its binary form is 11111110. If the number is odd, then its binary equivalent will end in 1. For e.g., the binary of 253 (an odd number) is 11111101.
Cross-verify the answers: Once the conversion is done, we can cross-verify the answers by converting the number back to the decimal form. This will eliminate any unforeseen errors in conversion.
Practice by using tables: Writing the decimal numbers and their binary equivalents on a table will help us remember the conversions.
Here, let us take a look at some of the most commonly made mistakes while converting numbers to binary.
Convert 253 from decimal to binary using the place value method.
11111101
2^7 is the largest power of 2, which is less than or equal to 253. So place 1 next to 2^7. Subtracting 128 from 253, we get 125. Find the next largest power of 2 for 125. The answer is 2^6. Continue this process until all numbers are used. By using this method, we can find the binary form of 253.
Convert 253 from decimal to binary using the division by 2 method.
11111101
Divide 253 by 2. In the next step, the quotient becomes the new dividend. Continue the process until the quotient becomes 0. Now, write the remainders upside down to get the final result.
Convert 253 to binary using the representation method.
11111101
Break the number 253 into powers of 2 and find the largest powers of 2. We get 2^7. So 1 is placed next to 2^7. Next, 253 - 128 = 125. Continue this process until the remainder is 0. After getting 0, fill in with zeros for unused powers of 2. By following this method, we get the binary value of 253 as 11111101.
How is 253 written in decimal, octal, and binary form?
Decimal form - 253 Octal - 375 Binary - 11111101
The decimal system is also called the base 10 system. In this system, 253 is written as 253 only. We have already seen how 253 is written as 11111101 in binary. So, let us focus on the octal system, which is base 8. To convert 253 to octal, we need to divide 253 by 8. So 253 / 8 = 31 with 5 as the remainder. In the next step, divide the quotient from the previous step (31) by 8. So 31 / 8 = 3 with 7 as the remainder. Finally, divide 3 by 8 to get 0 with 3 as the remainder. The division process stops here because the quotient is now 0. Here, 3, 7, and 5 are the remainders, and they have to be written in reverse order. So, 375 is the octal equivalent of 253.
Express 253 - 5 in binary.
11111010
253 - 5 = 248 So, we need to write 248 in binary. Start by dividing 248 by 2. We get 124 as the quotient and 0 as the remainder. Next, divide 124 by 2. Now we get 62 as the quotient and 0 as the remainder. Continue this process until the quotient becomes 0. Now write the remainders from bottom to top to get 11111010 (binary of 248).
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
: She loves to read number jokes and games.