Number Converter Suite
Comprehensive number system converter. Convert between binary, octal, decimal, hexadecimal, RGB/Hex colors, ASCII/Unicode characters, and signed integers.
About this calculator
This calculator bundles four independent number-representation tools behind one Conversion Type selector, since they all boil down to reformatting a number rather than doing real arithmetic on it. Number Base Conversion takes a single decimal Input Number and derives its binary, octal, and hexadecimal representations directly from JavaScript's own base-conversion routines, along with the bit and byte counts needed to store it and, when the value falls in the printable range, its ASCII character. Color Conversion works the other three modes -- RGB channels to hex/CSS/HSL strings, or a packed hex value back to individual RGB channels -- entirely independently of the Number Base mode's inputs; the two conversions never interact because the calculator only runs the branch matching the selected Conversion Type.
ASCII/Unicode Table walks a range of code points starting from a chosen Starting Code Point, useful for looking up a block of characters and their hex codes at once. Signed Integer converts a value to its two's complement binary and hexadecimal representation at a chosen bit width, clamping the input to whatever range that width can represent (for example, 8-bit two's complement spans -128 to 127) so an out-of-range entry doesn't silently overflow into a meaningless bit pattern.
Step 1 of 2
How to Use This Calculator
- Choose a Conversion Type: Number Base for binary/hex/decimal/octal, Color Conversion for RGB↔Hex, ASCII/Unicode Table, or Signed Integer (Two's Complement).
- For number base conversion, enter the Input Number in decimal and instantly see Binary, Octal, and Hexadecimal equivalents with bit/byte counts.
- For color conversion, enter Red, Green, Blue channel values (0–255) to get the Hex Color, RGB CSS, RGBA CSS, and HSL representations.
- For ASCII/Unicode, set the Starting Code Point (e.g., 65 for 'A') and Number of Characters to explore a range of characters with their hex codepoints.
- For signed integers, enter the Signed Value and select 8-bit, 16-bit, or 32-bit width to see the Two's Complement binary and hex encoding.
What each input means
- Conversion Type
- Calculation mode to use.
- Input Number
- Enter a decimal number to convert.
- Red (R)
- Red color channel (0-255).
- Green (G)
- Green color channel (0-255).
- Blue (B)
- Blue color channel (0-255).
- Hex Color Value
- Enter hex as decimal (e.g., 0x8080FF = 8421631).
- Starting Code Point
- Unicode code point to start from (65 = 'A').
How this is calculated
Worked example, using the default values
- Identify Input Parameters2 parametersConversion Type = 0, Input Number = 255 = 2 input(s) provided
- Calculate BinaryBinary = paddedBinary1111 1111 = 1111 1111
- Calculate HexadecimalHexadecimal = `0x${hex}`0xFF = 0xFF
- Calculate DecimalDecimal = decimalValue255 = 255
- Calculate OctalOctal = `0o${octal}`0o377 = 0o377
Engine last updated . Checked against 5 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
Why doesn't changing the Red, Green, or Blue inputs affect the Decimal output?
Because Conversion Type controls which independent branch of the calculator actually runs -- Number Base Conversion mode only reads Input Number, and Color Conversion mode only reads Red, Green, Blue, Alpha, or Hex Color Value depending on Color Mode. The two conversions share no formulas or intermediate values, so adjusting one mode's inputs never touches another mode's outputs.
How does Bits relate to Bytes in the Number Base result?
Bits is simply the length of the number's binary representation, and Bytes is that bit count divided by 8 and rounded up to the next whole byte, since a computer can only allocate storage in whole-byte increments. A value needing 9 bits (for example, 300 in binary) still needs 2 full bytes of storage, not 1.125.
What happens if I enter a Signed Value outside the selected Bit Width's range?
The calculator clamps it to the nearest valid boundary for that bit width rather than silently wrapping it -- an 8-bit signed integer can only represent -128 to 127, so entering 200 at 8-bit width is clamped to 127, the largest value that width can actually hold, and the two's complement binary and hex shown reflect that clamped value, not the original 200.
Is a larger Input Number always represented in more bits?
Yes, non-decreasingly: as Input Number grows across this calculator's declared range, the Bits and Bytes outputs never shrink, though they can stay flat across a span of values that all happen to fit the same bit count (255 and 128 both need exactly 8 bits, for instance) before stepping up once the value crosses the next power-of-two boundary.
Does the ASCII Character output always show a printable character?
No -- it only resolves a character for Input Number values between 32 and 126, the standard printable ASCII range, and shows "N/A" outside that range (control codes below 32, or anything above 126, which falls into extended ASCII or Unicode territory rather than basic printable ASCII).
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