Decimal to Octal Converter

The method

To convert a decimal number to octal, divide it by 8 again and again. Write down the remainder each time, and stop when the quotient reaches 0. Then read the remainders from the last to the first.

100 / 8 = 12 remainder 4
 12 / 8 =  1 remainder 4
  1 / 8 =  0 remainder 1
Read upward: 144

So 100 in decimal is 144 in octal. You can check it: 1 x 64 + 4 x 8 + 4 = 100.

The table shows every step

The working table above lists each division, its quotient and its remainder, so you can follow the method or check homework. Negative numbers are converted by their size and keep the minus sign.

Common values

• 8 is 10
• 10 is 12
• 16 is 20
• 64 is 100
• 255 is 377
• 512 is 1000

Powers of 8 become a 1 followed by zeros, just as powers of 10 do in decimal.

Batch conversion

Paste a list of decimal numbers, one per line, to convert them all at once. Whole numbers only.

To go back, use octal to decimal. For all four bases at once, use the octal converter.