Decimal to binary
Input
255Output
11111111 (or 11111111 with 8-bit padding)255₁₀ = 11111111₂ = FF₁₆ = 377₈.
Unsigned integers and Unicode code points only. No signed two’s-complement widths and no fractional radix conversion. Large integers use BigInt for exact digit output.
Skip to number base converterConvert between binary, decimal, octal, hexadecimal, and any radix from 2–36. Paste one value or many tokens—live auto-convert, optional byte padding, and exact BigInt results for large integers.
Positional number systems use different digit alphabets for the same value. Binary uses 0–1, octal 0–7, decimal 0–9, and hexadecimal 0–9 plus A–F. Custom bases up to 36 add A–Z.
**This free number base converter** handles:
Use it for homework checks, bitmask inspection, Unix permission octals, hex dumps, and protocol fields—not for hex color pickers or signed two’s-complement widths.
One page owns integer radix conversion. For encoding whole strings as binary bitstreams, use Text to Binary; for CSS colors, use Color Picker.
Students & CS courses
Verify binary to decimal, decimal to binary, and hex conversions against class examples.
Software developers
Convert hex constants to decimal/binary or binary flags to hex when reading logs and registers.
Sysadmins
Translate octal permission values (e.g. 755) to binary bit patterns or decimal for documentation.
Embedded & security
Convert 64-bit hex values to exact decimal with BigInt instead of rounded floating-point math.
Input
255Output
11111111 (or 11111111 with 8-bit padding)255₁₀ = 11111111₂ = FF₁₆ = 377₈.
Input
1010Output
101×8 + 0×4 + 1×2 + 0×1 = 10.
Input
FFOutput
25515×16 + 15 = 255.
Input
16Output
1016₁₀ = 10₁₆ = 10000₂ = 20₈.
Input
1010Output
ANibble 1010 maps to hex digit A.
Step-by-step chains that connect related tools for common tasks.
Same unsigned integers shown in binary, octal, decimal, and hex.
| Decimal | Binary | Octal | Hex |
|---|---|---|---|
| 10 | 1010 | 12 | A |
| 15 | 1111 | 17 | F |
| 16 | 10000 | 20 | 10 |
| 32 | 100000 | 40 | 20 |
| 64 | 1000000 | 100 | 40 |
| 128 | 10000000 | 200 | 80 |
| 255 | 11111111 | 377 | FF |
| 256 | 100000000 | 400 | 100 |
| 1024 | 10000000000 | 2000 | 400 |
Enter any of these values above to convert live. Padding options can add leading zeros for binary/hex display.
Keep number-base intent separate from encoding and color tools.
| Need | Use this page | Use instead |
|---|---|---|
| Binary ↔ decimal ↔ hex ↔ octal integers | Yes | — |
| Custom bases 2–36 | Yes | — |
| Text string ↔ binary bit stream | No | Text to Binary |
| Text ↔ hex dump / UTF-8 bytes | Code points only | Text to Hex |
| Pick CSS HEX/RGB colors | No | Color Picker |
| IPv4 integer / dotted quad | No | IP Converter |
Enable 8-bit padding so each token aligns to a byte boundary in dumps and packet captures.
One hex digit = 4 bits; two hex digits = one byte—handy for memory and protocol fields.
Copy the share link so teammates restore the same bases, padding, and input.
Values are unsigned. Apply bit-width rules yourself or use a dedicated signed/bitwise tool.
Watch for the BigInt banner—EverydayTools keeps large integers exact.
Text mode emits scalar values. For byte dumps of strings, prefer Text to Hex / Text to Binary workflows.
Use Text to Binary for 8-bit binary strings of text.
Use Color Picker for HEX/RGB/HSL swatches and design tokens.
Use IP Converter for dotted-quad address math.
This tool is integer-only (plus Unicode code points in text mode).
Parse digits in the source radix into an integer (BigInt), then format that integer in the target radix. Single-value mode also shows the decimal intermediate.
Formula
value = Σ (digitᵢ × sourceRadixⁱ)
output = value.toString(targetRadix)Pick Binary, Decimal, Octal, Hexadecimal, Custom (2–36), or Text. Example: Decimal → Binary or Hexadecimal → Decimal.
Type integers separated by spaces or newlines. Optional 0x / 0o prefixes are stripped on input for hex and octal tokens.
Results update live. For a single value, review the via-decimal breakdown when shown.
Copy output, swap direction using the latest result, or copy a share URL. Nothing is uploaded for normal use.
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Multiply each bit by its power of 2 and add (or paste binary here with Binary → Decimal). Example: 1010₂ = 8+2 = **10**₁₀.
Repeatedly divide by 2 and read remainders, or enter a decimal value with Decimal → Binary. Example: **10**₁₀ → **1010**₂. Enable 8-bit padding when you want byte-aligned bits.
Treat each hex digit as base 16 (A=10 … F=15). Example: **FF**₁₆ = 15×16+15 = **255**₁₀. Select Hexadecimal → Decimal in the converter.
Divide by 16 and map remainders to 0–9/A–F, or use Decimal → Hexadecimal. Example: **255**₁₀ → **FF**₁₆.
Group bits in fours from the right and map each nibble to one hex digit (1010 → A), or convert Binary → Hexadecimal here.
Presets for binary (2), octal (8), decimal (10), and hexadecimal (16), plus **custom radix 2–36**. Digits use 0–9 and A–Z.
Radix means the base of a numeral system—the number of unique digits. Binary has radix 2; hex has radix 16.
Yes. Values above JavaScript’s safe integer (2⁵³−1) use **BigInt** so every digit stays exact. A banner appears when BigInt mode is active.
No. This tool targets non-negative integers. Signed two’s-complement layouts need an explicit bit-width tool or language REPL.
No. Text mode here maps characters to Unicode **code points** in a chosen base. Encoding a whole string as an 8-bit binary bitstream belongs on Text to Binary.
You can convert a channel like FF → 255, but full color picking (HEX/RGB/HSL swatches) belongs on Color Picker—not this radix tool.
Yes. Free, no signup. Conversion, history, and local .txt reads run in your browser and are not uploaded to EverydayTools servers for normal use.
Conversions, history, autosave, and local .txt reads run in your browser—nothing is uploaded to EverydayTools servers for core use.
Positional notation with BigInt for integers beyond Number.MAX_SAFE_INTEGER. Text mode uses Unicode scalar values, not UTF-8 byte sequences.
Parsing and formatting run client-side after you enter values.
Educational developer utility. Not a signed fixed-width ALU simulator, float inspector, or cryptographic tool.
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Reviewed by EverydayTools Editorial Team on 2026-09-06.
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