Hex, decimal, octal, binary converter
Convert among hexadecimal, decimal, octal, and binary. Free online tool — no sign-up. Clear formulas and worked examples. Runs locally in your browser.
Enter values to convert.
Formulas
Core equations used by this converter.
How to use
Open the converter
Use the interactive panel at the top of the page.
Enter values
Fill in the required fields for this conversion.
Convert and read the result
Use Convert or let the result update automatically.
Example conversions
Common values with formula and result.
Hex `A` → all forms
Hex `A` → all forms
Binary `11111111` → hex / octal / decimal
Binary `11111111` → hex / octal / decimal
Decimal `100` → hex
Decimal `100` → hex
Hex, decimal, octal, binary converter specification
Version 1.1.0 · Engine tested
- Engine tested 3 published cases
- Named expert review Not performed
- Calculation version 1.1.0
- Definition
- | Base | Name | Digits | | --- | --- | --- | | 2 | Binary | 0, 1 |
- What it calculates
- Convert among hexadecimal, decimal, octal, and binary. Positional notation and bit-grouping shortcuts, with a multi-base reference table.
- Inputs
- Values required by the selected conversion mode
- Outputs
- Converted result in the target unit or format
- Formula
decimal = Σ dᵢ · bⁱ- Hex / decimal / octal / binary table
Base Name Digits 2 Binary 0, 1 8 Octal 0–7 10 Decimal 0–9 16 Hex 0–9, A–F - Assumptions
- Conversion runs locally in the browser; values are not uploaded.
- Uses the formulas documented on this page.
- Units
- Formula
- Boundary conditions
- Empty or invalid input yields no valid result.
- Out-of-range values may be rejected by the tool runtime.
- Example
- Hex `A` → all forms → 1010₂
- Validation cases
- Hex `A` → all forms → 1010₂
- Binary `11111111` → hex / octal / decimal → 255₁₀
- Decimal `100` → hex → 64₁₆
- Sources
- CalculatorX converter runtime
- Standard unit / encoding definitions where applicable
- Calculation version
- 1.1.0
Background
Interpretation and common distinctions.
Use the converter tabs to switch direction when available. Results for Hex, decimal, octal, binary converter update locally in your browser.
Related tools
Frequently asked questions
Key distinctions behind the conversion.
How do you convert using Hex, decimal, octal, binary converter?
Use decimal = Σ dᵢ · bⁱ. Example: Hex `A` → all forms → 1010₂.
Can I switch direction?
Open the related reverse converter listed under Related tools.
Does this run online or locally?
Calculation runs locally in your browser. Values are not uploaded.
How precise are the results?
Results follow the formulas on this page. Round to the precision your use case needs.