Convert numbers between binary, octal, decimal, hexadecimal, and any base from 2 to 36.
The digits must be valid in the chosen "from" base.
From Base — Value for from base. Provide accurate numbers for a reliable Converted Value. Example: 16.
To Base — Value for to base. Provide accurate numbers for a reliable Converted Value. Example: 2.
Converted Value
11111111
Converted Value — Calculated outcome. Derived from your inputs via the displayed formula; use to plan.
Decimal (Base 10)
255
Decimal (Base 10) — Calculated outcome. Derived from your inputs via the displayed formula; use to plan.
A positional number system uses a base (radix) that defines how many digits each place can hold. This converter works for any base from 2 up to 36, using digits 0–9 followed by A–Z.
Formula
(dₙ…d₂d₁d₀)_b = dₙ·bⁿ + … + d₁·b¹ + d₀·b⁰
Worked examples
FAQ
What digits are allowed above 9?
Base 10 and above use letters: A = 10, B = 11, … up to Z = 35, which supports bases up to 36.
Why do large values stay exact?
The conversion uses BigInt arithmetic, so numbers thousands of digits long convert without floating-point rounding.