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Binary to Decimal Converter

Convert between binary, octal, decimal and hex in one place.

Processed locally — nothing is uploaded

About Number Base Converter

All four bases update together, and the bitwise side runs AND, OR, XOR, NOT and shifts across two values. BigInt underneath means numbers past 2^53 stay exact instead of quietly rounding.

Convert a binary number to decimal — and to hex and octal — at once, with a bitwise calculator alongside. It uses BigInt so even very large values stay exact, all computed in your browser.

Convert any integer between binary, octal, decimal and hexadecimal all at once, and run AND, OR, XOR, NOT and bit-shift operations on two values. It is an essential helper for low-level programming, embedded work, networking masks and debugging bit flags.

All four bases stay in sync as you type, so one value can be read in each without converting twice. The bitwise panel earns its place when you are working with permission bits, feature flags or network masks.

Learn how this works

A Practical Guide to Everyday Developer Encoding & FormattingHow and when to use Base64, JSON formatting, hashing, JWTs, regex and cron — with free in-browser tools for each task.11 min read

Frequently asked questions

How does binary to decimal conversion work?

Each digit is a power of two, read right to left: 1011 is (1x8) + (0x4) + (1x2) + (1x1) = 11. Doing it by hand is a good way to build intuition, but error-prone past a few digits.

Why do computers use binary at all?

Because a transistor reliably represents two states — on and off — while distinguishing ten voltage levels would be far more error-prone. Everything else, including the decimal numbers you see, is built on top of that.

What is the largest number a byte can hold?

255 for an unsigned byte: eight bits, all ones, is 128+64+32+16+8+4+2+1. Signed bytes spend one bit on the sign, giving a range of -128 to 127, which is where a surprising number of overflow bugs come from.

Common Use Cases

  • •Checking your working on a computer science assignment
  • •Reading a binary flag or bitmask from a log or protocol dump
  • •Understanding a permissions value or register dump while debugging

More Number Base Converter tools

Number Base ConverterHex to Decimal ConverterBitwise Calculator

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