What does the Binary / Hex / Decimal Converter do?

Convert between binary, decimal, hexadecimal and octal number systems instantly. All calculations are performed in your browser using official UK rates and thresholds.

How accurate are the results?

This calculator uses standard mathematical algorithms and provides results accurate to the precision shown. For very large numbers or high-precision requirements, results are rounded to a reasonable number of decimal places.

Can I use this for schoolwork?

Yes. This calculator is suitable for GCSE, A-level and university-level mathematics. It follows standard mathematical conventions used in UK education.

Binary / Hex / Decimal Converter

Convert between binary, decimal, hexadecimal and octal number systems instantly.

Last updated: April 2026 · Source: BBC Bitesize — Binary and data representation

Input

Input Base

Decimal

255

Binary

11111111

Hexadecimal

Octal

377

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

Binary (base-2) uses only 0 and 1 to represent numbers. Each position represents a power of 2, starting from the right: 1, 2, 4, 8, 16 and so on. This converter translates between binary, decimal (base-10), octal (base-8) and hexadecimal (base-16).

Binary is the foundation of all digital computing — every piece of data in a computer is ultimately stored as a sequence of binary digits (bits). Hexadecimal is commonly used in programming as a shorthand for binary, where each hex digit represents exactly four bits.

Example: Converting decimal 255

Decimal 255 = Binary 11111111
Decimal 255 = Octal 377
Decimal 255 = Hexadecimal FF
11111111 in binary = 128+64+32+16+8+4+2+1 = 255

Source: BBC Bitesize — Binary and data representation

Frequently Asked Questions

What does the Binary / Hex / Decimal Converter do?: Convert between binary, decimal, hexadecimal and octal number systems instantly. All calculations are performed in your browser using official UK rates and thresholds.
How accurate are the results?: This calculator uses standard mathematical algorithms and provides results accurate to the precision shown. For very large numbers or high-precision requirements, results are rounded to a reasonable number of decimal places.
Can I use this for schoolwork?: Yes. This calculator is suitable for GCSE, A-level and university-level mathematics. It follows standard mathematical conventions used in UK education.