How to use the Hex to Decimal Converter
- Type the hex value — with or without 0x — in the hexadecimal field.
- Read the decimal, binary and octal values, updated as you type.
- Type in the decimal field to convert the other way.
How hex to decimal works
Hexadecimal is base 16: the digits 0–9 and the letters A–F (10–15). Each position is worth 16 times the one to its right. 1A3F = 1×4096 + 10×256 + 3×16 + 15×1 = 6,719. Two hex digits make exactly one byte, which is why hex is used for colors (#FF8800), memory addresses and byte dumps.
Large numbers and negative values
The converter uses arbitrary-precision integers, so 64-bit and larger values convert exactly — no rounding as in a regular calculator. For signed values, the two’s-complement view shows how a value like FFFFFFFF reads as −1 in a 32-bit signed integer.
Quick reference
0xFF = 255 · 0x100 = 256 · 0xFFFF = 65,535 · 0x7FFFFFFF = 2,147,483,647 (largest signed 32-bit integer).
Tools that pair well with the Hex to Decimal Converter
- HEX to RGBA Converter — Paste a HEX code, drag the opacity slider and copy the exact CSS you need — legacy rgba(), modern rgb( / alpha) or 8-digit HEX.
- Binary to Text Converter — Paste binary code — groups of eight 0s and 1s, or one long string — and read it as text.
- Text to Binary Converter — Type text to see it as binary code, or paste binary (or hex, octal, decimal) to translate it back to readable text.
- Chmod Calculator — Tick read, write and execute for owner, group and others — or type 755, rwxr-xr-x or u=rwx,g=rx,o=rx.
Frequently asked questions
What is FF in decimal?
255 — F is 15, so FF = 15×16 + 15.
How do I convert decimal to hex?
Type the number in the decimal field. Manually, divide by 16 repeatedly and write the remainders from last to first.
What does the 0x prefix mean?
It marks a hexadecimal number in code (C, JavaScript, Python). The converter accepts values with or without it.
Can I install Hex to Decimal Converter as a web app and use it offline?
Yes. Hex to Decimal Converter is an installable web app (PWA) — installed from your browser, not downloaded from an app store. Click Install app at the top of this page in Chrome or Edge (Windows, macOS, Linux, ChromeOS) or on Android, use Share → Add to Home Screen on iPhone and iPad, or File → Add to Dock in Safari 17+ on a Mac. It then opens in its own window with its own icon, and because it runs entirely in your browser it keeps working offline. Firefox on desktop can’t install web apps. How installing works.