What is 377 octal in binary?

377 in octal (base 8) equals 11111111 in binary (base 2), which is 255 in decimal.

How do I convert octal to binary by hand?

Convert octal to decimal first (377 = 255), then convert that decimal value to binary (255 = 11111111). The tool above does both steps for you.

Is this exact for very large numbers?

Yes. The converter uses big-integer (BigInt) arithmetic in your browser, so even very long octal values convert to binary with no rounding or precision loss.

Which characters are valid in octal?

Base-8 octal uses the digits 0–7. Spaces, underscores and an optional 0x/0b/0o prefix are ignored; any other character is flagged as invalid.

Octal to Binary Converter

Convert a octal (base 8) number to binary (base 2) instantly. As an example, 377 = 11111111. It runs entirely in your browser.

Octal value

Binary result

Base	This number
Binary (base 2)	`—`
Octal (base 8)	`—`
Decimal (base 10)	`—`
Hexadecimal (base 16)	`—`

How to convert octal to binary

The simplest route from octal to binary goes through decimal: convert the octal value to decimal, then convert that to binary.

377 (octal) = 255 (decimal) = 11111111 (binary)

Worked example: 377 in binary

Reading 377 as base 8: 3 × 8² (= 192) + 7 × 8¹ (= 56) + 7 × 8⁰ (= 7) = 255 in decimal, which is 11111111 in binary.

More octal-to-binary examples: 12 = 1010, 20 = 10000, 100 = 1000000.

Binary, octal, decimal & hexadecimal reference table

Decimal	Binary	Octal	Hex
1	`1`	`1`	`1`
2	`10`	`2`	`2`
4	`100`	`4`	`4`
8	`1000`	`10`	`8`
10	`1010`	`12`	`A`
15	`1111`	`17`	`F`
16	`10000`	`20`	`10`
32	`100000`	`40`	`20`
64	`1000000`	`100`	`40`
100	`1100100`	`144`	`64`
128	`10000000`	`200`	`80`
255	`11111111`	`377`	`FF`
256	`100000000`	`400`	`100`
1024	`10000000000`	`2000`	`400`

About octal and binary

Octal: Octal is base-8, using digits 0–7. Each octal digit maps to exactly three bits, which is why it appears in Unix file-permission modes such as 755.

Binary: Binary is base-2: every digit (bit) is 0 or 1. It is how computers store and process all data at the hardware level.

Frequently asked questions

What is 377 octal in binary?: 377 in octal (base 8) equals 11111111 in binary (base 2), which is 255 in decimal.
How do I convert octal to binary by hand?: Convert octal to decimal first (377 = 255), then convert that decimal value to binary (255 = 11111111). The tool above does both steps for you.
Is this exact for very large numbers?: Yes. The converter uses big-integer (BigInt) arithmetic in your browser, so even very long octal values convert to binary with no rounding or precision loss.
Which characters are valid in octal?: Base-8 octal uses the digits 0–7. Spaces, underscores and an optional 0x/0b/0o prefix are ignored; any other character is flagged as invalid.

Related number conversions

See all number-base conversions →