Binary is base 2 and uses only digits 0 and 1.

Which symbols does hexadecimal use?

It uses digits 0–9 and letters A–F for values 10–15.

Which letters can custom bases use?

Through base 36, letters represent A=10, B=11, through Z=35.

Can negative numbers be converted?

Yes. The leading minus sign is preserved.

Are large numbers rounded?

No. Conversion uses exact BigInt integer arithmetic.

Can binary contain digit 2?

No. Base 2 accepts only 0 and 1.

Tools/🧮 Calculators/Number Base Converter

Number Base Converter

Convert binary, octal, decimal, hexadecimal, and custom bases from 2 through 36 exactly.

Version 1.0 · Last Updated: August 11, 2026 · Maintained by ToolLarder

Binary, decimal, hexadecimal, and custom base conversion

Read an integer in its source base and convert it to every standard representation plus a selected target base from 2 to 36. BigInt prevents rounding.

Binary and decimal conversion

Binary uses only 0 and 1, with each position weighted by a power of 2.

(1011)₂ = 11₁₀

Hexadecimal conversion

Hexadecimal uses 0–9 and A–F and is common in software.

(FF)₁₆ = 255₁₀

Octal conversion

Octal uses digits 0 through 7.

(755)₈ = 493₁₀

Custom base conversion from 2–36

Digits above 9 use A=10 through Z=35.

value = Σ digit×baseᵏ

Exact large integer results

BigInt preserves integers beyond the JavaScript Number limit without rounding.

integer → exact BigInt