Number System Converter
developer
Convert binary, octal, decimal, hexadecimal, and character values quickly, including fractional numeric input.
Result
Universal guide (example: binary → hexadecimal)
Three steps: symbols → the right math move for this pair → worked examples you can copy on paper. Numeric bases (binary, octal, decimal, hex) also support one radix point and digits after it; character mode stays a single code unit.
Step 1 — Identify the symbols
Input (Binary): Each position is either 0 or 1.
Output (Hexadecimal): Digits 0–9 plus letters A–F for values ten through fifteen.
Hex conversions use this letter-to-number map:
| Digit | Value | Digit | Value |
|---|---|---|---|
| 0 | 0 | 8 | 8 |
| 1 | 1 | 9 | 9 |
| 2 | 2 | A | 10 |
| 3 | 3 | B | 11 |
| 4 | 4 | C | 12 |
| 5 | 5 | D | 13 |
| 6 | 6 | E | 14 |
| 7 | 7 | F | 15 |
- Many tools allow a 0b prefix (e.g. 0b1010).
- 0x is a common prefix (e.g. 0xFF).
Step 2 — The Two-Step Method (via Decimal)
. for a fractional part is allowed on numeric bases), then rewrite that value in the right format. The calculator automates both steps.Part A — Into decimal
Number positions from the right, starting at 0. At each position, multiply that digit by 2 raised to the position index, then add every term. The total is your decimal number.
Digits after the dot: use negative powers of 2 (2−1, 2−2, …). Each place is still (digit × weight); add the fractional side to the whole side.
Part B — Out of decimal
Repeated division by 16: each remainder is one hex digit; values 10– 15 become A–F. Read remainders from last step to first.
Fractional decimal values: convert the whole part with repeated division, then multiply the fractional part by the target base over and over; each integer you get is the next digit after the radix point (same idea the calculator shows in Formulas).
Step 3 — Worked examples
Two practice values in Binary, converted to Hexadecimal using the same rules as Step 2. Example 3 uses a fractional part (digits after the radix point); the hub and pair calculators accept a single . on binary, octal, decimal, and hex inputs.
Example 1
"1010" (Binary) → Hexadecimal.
Toward decimal
Binary "1010"
= 1×2³ + 0×2² + 1×2¹ + 0×2⁰
= 8 + 2
= 10 (decimal)From decimal to output
Whole part — repeated division:
10 ÷ 16 = 0 R 10 (A)
Read remainders bottom → top → A
→ tool: 0xaVerify: "1010" → 0xa
Example 2
"1111" (Binary) → Hexadecimal.
Toward decimal
Binary "1111"
= 1×2³ + 1×2² + 1×2¹ + 1×2⁰
= 8 + 4 + 2 + 1
= 15 (decimal)From decimal to output
Whole part — repeated division:
15 ÷ 16 = 0 R 15 (F)
Read remainders bottom → top → F
→ tool: 0xfVerify: "1111" → 0xf
Example 3
"1010.101" (Binary) → Hexadecimal.
Toward decimal
Binary "1010.101"
Left of . : 1×2³ + 0×2² + 1×2¹ + 0×2⁰ = 10
Right of .: 1×2^-1 + 0×2^-2 + 1×2^-3 = 0.5 + 0.125
= 10.625 (decimal)From decimal to output
Whole part — repeated division:
10 ÷ 16 = 0 R 10 (A)
Read remainders bottom → top → A
Fractional part — multiply by 16, integer of each product = next digit after .
0.625×16 = 10 → A
Digits after . (in order): .A
→ tool: 0xa.aVerify: "1010.101" → 0xa.a
Every dedicated pair below uses this same three-step layout with bases filled in for that page.
Dedicated converters (binary, octal, decimal, hexadecimal, character)
20 pages — every directed pair of formats below, with fixed input/output and the same parsing rules as the main converter (including optional fractional input on numeric bases).
- bin to oct (Binary to Octal)
- bin to dec (Binary to Decimal)
- bin to hex (Binary to Hexadecimal)
- bin to char (Binary to Character)
- oct to bin (Octal to Binary)
- oct to dec (Octal to Decimal)
- oct to hex (Octal to Hexadecimal)
- oct to char (Octal to Character)
- dec to bin (Decimal to Binary)
- dec to oct (Decimal to Octal)
- dec to hex (Decimal to Hexadecimal)
- dec to char (Decimal to Character)
- hex to bin (Hexadecimal to Binary)
- hex to oct (Hexadecimal to Octal)
- hex to dec (Hexadecimal to Decimal)
- hex to char (Hexadecimal to Character)
- char to bin (Character to Binary)
- char to oct (Character to Octal)
- char to dec (Character to Decimal)
- char to hex (Character to Hexadecimal)
Common questions (FAQ)
10 quick answers with guides and links to the matching converter.
- How to convert decimal to binary with steps
- Decimal to hexadecimal converter for rgb colors
- Binary to string converter for text messages
- Hex to ASCII character conversion online
- Convert decimal fraction to binary converter
- How to convert 8 bit binary to decimal
- Excel decimal to hex function dec2hex guide
- Convert integer to character in base 10
- Binary to octal converter with calculation table
- Long decimal to binary converter for large numbers
Number System Converter Guide
If you also need text encoding checks, open the ASCII Code Converter and Base64 Encoder & Decoder.
Quick start
- Select input format (Input as): Binary, Octal, Decimal, Hexadecimal, or Character.
- Enter a value. Numeric examples: 0b1010, 0xFF, 0777, 255 — you may add one dot for a fraction (e.g. 1010.101 in binary, 10.625 in decimal). Character: exactly one symbol, no dot.
- All conversions are shown at once. Copy All to copy. Clear to reset.
Dedicated pair pages & FAQ
Need a fixed input/output pair (e.g. binary to hex only)? Use a dedicated converter from the list below.
Common questions are linked in the FAQ section below; each opens a short article with tables and links to the matching pair page.
Example uses
- Programming: convert between number bases.
- Debugging: inspect character codes.
- Learning: understand number systems and fractional radix (e.g. binary fractions).