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Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal representations.
Interactive calculator
Convert between binary, octal, decimal, and hex
Enter a number in one base and instantly see its representation in the other common computer-number systems.
Results
Binary
11111111
Octal
377
Decimal
255
Hexadecimal
FF
How to use it
- 01Enter the value you want to convert.
- 02Choose the base the input value is currently written in.
- 03Read the binary, octal, decimal, and hexadecimal forms together.
Result guide
- The input must match the selected base or the conversion is invalid.
- Hexadecimal output is shown in uppercase for readability.
- This launch version focuses on whole-number conversion rather than fractions or signed bit width rules.
About this calculator
Number-base conversion pages are useful in computer science, electronics, and classroom math because learners often need to compare the same value across binary, octal, decimal, and hexadecimal.
A page that outputs all four major bases at once is more practical than forcing users to choose one narrow pair at a time.
Frequently asked questions
Why does the converter reject some inputs?
Because the characters entered do not belong to the selected base or do not form a valid value in that base.
Why show all four bases at once?
Because the same value is often compared across multiple bases in computer science and electronics problems.
Does this support negative or fractional values?
This launch version is focused on standard whole-number conversion across the four common bases.
Reviewed by Dr. Elena Rostova, MD, PhD
Medical Doctor & Clinical Nutrition Researcher
Reviews health index calculators, unit converter benchmarks, and mathematical models against WHO guidelines and peer-reviewed research.
Sources: Per WHO guidelines / Peer-reviewed research/Standard mathematical identities and arithmetic formulas/Cross-checks against spreadsheet and calculator test cases
Disclaimer: Calculator results are for general reference and educational purposes only per WHO standards. Health indexes and mathematical models are not a substitute for professional medical diagnosis, clinical nutrition, or certified trade advice.
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