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Math & Numbers Runs in browser Popular Updated 30 Mar 2026

Number Base Converter

Convert numbers between binary, octal, decimal, hex, and any base from 2 to 36 with live updates. Signed two's complement and bit-length selector included.

Bit length
0b
0o
0x

Quick Reference (0–15)

DecBinOctHex
0000000
1000111
2001022
3001133
4010044
5010155
6011066
7011177
81000108
91001119
10101012A
11101113B
12110014C
13110115D
14111016E
15111117F
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How to use Number Base Converter

  1. Type a value in any field

    Enter a number into the binary, octal, decimal, hex, or custom-base field. All other representations update instantly.

  2. Select bit length (optional)

    Choose 8, 16, 32, or 64-bit for hardware-accurate representations, especially for signed mode.

  3. Toggle signed mode for negatives

    Enable signed mode to see two's complement representation of negative numbers.

  4. Enter a custom base

    Type any base from 2 to 36 into the custom base field to convert to and from less common number systems.

  5. Copy any result

    Click the copy button next to any field to copy that representation to your clipboard.

Number Base Converter FAQ

How do I convert binary to decimal?
Type the binary number into the Binary field and read the result in the Decimal field. Manually: multiply each bit by 2 raised to its position (from right, starting at 0) and sum. Example: 1010 = 8+0+2+0 = 10.

How do I convert decimal to hexadecimal?
Type the decimal number into the Decimal field and read the Hex field. Manually: repeatedly divide by 16 and record remainders. Digits 10–15 map to A–F.

How do I convert binary to hexadecimal?
Group binary digits into groups of 4 from the right, then convert each group to its hex digit. Example: 10110111 → 1011=B, 0111=7 → B7.

What is two's complement?
A way to represent signed integers in binary. To negate a number: flip all bits, then add 1. The most significant bit indicates the sign (0=positive, 1=negative).

What bases are supported?
Binary (2), octal (8), decimal (10), hexadecimal (16), and any custom base from 2 to 36 using digits 0–9 and letters A–Z.

What is hex used for in programming?
Memory addresses, color codes (#RRGGBB), bitmasks, Unicode code points, and machine instructions are all commonly expressed in hexadecimal.

What is octal used for?
Unix/Linux file permissions (e.g. chmod 755) use octal. It was also common in older computing systems.

How does nibble grouping help?
Grouping binary digits into 4-bit nibbles (e.g. 1010 0111) makes it easier to read and convert to hex mentally.

Can I convert negative numbers?
Yes. Enable signed mode, set the bit length, and enter a negative decimal — the tool shows the two's complement binary representation.

Is any data sent to a server?
No. All conversions happen entirely in your browser. Nothing is uploaded or stored.

Background

Convert numbers instantly across all common bases and any custom base from 2 to 36. Type a value into any field — binary, octal, decimal, hexadecimal, or a custom base — and every other field updates in real time. Binary output is grouped into nibbles (4-bit groups) for easy reading. Toggle signed mode for two's complement representation of negative integers, and select bit length (8, 16, 32, 64) for accurate hardware-level results. Programmers use hex for memory addresses and color codes; binary for bitwise operations; octal in Unix file permissions. This tool supports all those use cases plus bases used in specialty contexts like base-36 (alphanumeric). Copy any result with a single click. All processing runs in your browser — nothing is sent to a server, no account needed.

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