number base converter
Octal and Decimal are two of the numbering systems used constantly in computing, electronics, and low-level programming. This tool converts a octal number (base 8) into its exact decimal (base 10) equivalent, handling the place-value math so you don't have to work it out by hand.
Every number system represents a quantity using positional place values raised to powers of its base. Octal uses base 8, meaning each digit position represents a power of 8. To convert into decimal (base 10), the value is first reduced to a plain decimal quantity, then re-expressed using base-10 digits. This tool performs that two-step conversion instantly and validates that your input only contains digits valid for base 8.
Binary and hexadecimal show up throughout software development — file permissions, color codes, memory addresses, and low-level debugging output are commonly shown in hex because it's a compact, human-readable stand-in for binary data. Octal appears in older Unix file-permission notation and some embedded systems. Decimal is the everyday counting system most people think in, which is why converting to and from it is usually the first step in translating between any two non-decimal bases.
Developers reach for a converter like this when reading a hex dump, setting file permissions, working with color values, or double-checking a manual calculation before it ends up in production code.
Only the digits 0 through 7 are valid in octal.
This tool is built for standard unsigned positive values. Negative numbers in binary typically use two's complement representation, which depends on a fixed bit width.
Very large numbers are supported up to standard JavaScript integer precision limits, which comfortably covers typical use cases like memory addresses and color values.
ToolBench runs this tool entirely in your browser. Your file or text is processed on your own device using JavaScript — nothing is uploaded to a server, nothing is stored, and there's no sign-up wall between you and the result. That's true of every one of the 500+ tools on this site, from PDF utilities to unit converters.