Mathematical Tools
What It Does
Converts a number between binary, octal, decimal, hex, and any base from 2 to 36 — all at once, in your browser. Optionally interprets the value as a fixed-width signed (two’s-complement) integer. Nothing is uploaded.
How to Use It
- Type your value and choose the base it’s written in.
- Pick which output bases to show (binary/octal/decimal/hex are on by default).
- Toggle Grouping for readability, or Signed + a Width to work in two’s-complement.
- Click Copy on any row to grab it.
Options Explained
| Option | Description |
|---|---|
| Value | The number to convert. You can paste with 0x/0o/0b prefixes or grouped digits. |
| In base | The base your value is written in (2–36). |
| Output bases | Which bases to display the result in. |
| Grouping | Adds spaces between digit groups for readability (doesn’t change the value). |
| Signed | Interpret/emit as a fixed-width two’s-complement integer. |
| Width | The bit width (8/16/32/64) used when Signed is on. |
-1 becomes all 1-bits (FF, FFFF, …) in two’s-complement.About Number Bases — Positional Notation & Two’s Complement
A number base (or radix) is just how many distinct digits a place-value system uses before it “carries” to the next column. Decimal (base 10) uses 0–9; binary (base 2) uses 0–1; hexadecimal (base 16) uses 0–9 then A–F. In every base, each digit’s worth is its face value times the base raised to the digit’s position — so hex FF3A is 15·16³ + 15·16² + 3·16¹ + 10·16⁰ = 65338.
Programmers reach for hex and binary constantly because they map cleanly onto how computers store data: one hex digit is exactly four bits (a “nibble”), so a byte is two hex digits. Negative integers are usually stored in two’s complement, where the top bit carries negative weight; that’s why, at a fixed width, -1 is represented as all 1-bits (FF in 8-bit, FFFF in 16-bit). Because this tool uses arbitrary-precision integers, it converts numbers far larger than a normal 64-bit value exactly, with no rounding — and, like every tool here, it runs entirely on your device.