How to Convert Numbers Between Bases (2 to 36)

To convert a number between bases, pick the base it's written in now (the from-base), pick the base you want (the to-base), type the number using valid digits, and read the converted result instantly. The ByteTools Number Base Converter does this for every base from 2 to 36 — binary, octal, decimal, hexadecimal and beyond — using exact arithmetic, entirely inside your browser. Here's the full walkthrough.

Because it all runs locally, nothing you type is uploaded or stored, so the ByteTools Number Base Converter is private, instant and works even offline.

What a number base actually is

A base (or radix) is how many distinct digits a numeral system uses before it rolls over to the next place. Decimal is base 10 — digits 0 through 9. Binary is base 2, using only 0 and 1. Once a base exceeds 10, letters step in as extra digits: hexadecimal (base 16) uses A–F for the values 10 to 15, and base 36 runs all the way to Z for 35. Every base is just a different way of writing the same underlying quantity.

Step-by-step: converting a number

1. Choose the from-base. Select the base your number is currently written in — for example base 2 if you have a binary string.
2. Choose the to-base. Select the base you want the answer in, such as base 16 for hexadecimal.
3. Type the number. Enter it using only digits valid for the from-base. In binary that's 0 and 1; in hex it's 0–9 and A–F.
4. Read the result. The converted value appears immediately, along with its decimal equivalent for reference.
5. Copy it. Click to copy the result to your clipboard for use elsewhere.

Worked example: binary to hexadecimal

Say you have the binary number 11010110 and want it in hex. Set from-base to 2, to-base to 16, and type the digits. The tool returns D6, and shows the decimal equivalent 214 so you can sanity-check it. No manual grouping of bits into nibbles required — though doing it by hand (1101 = D, 0110 = 6) confirms the answer.

Common conversions at a glance

From	To	Example input	Result
Binary (2)	Decimal (10)	1010	10
Decimal (10)	Hex (16)	255	FF
Hex (16)	Binary (2)	1F	11111
Decimal (10)	Octal (8)	64	100
Decimal (10)	Base 36	1295	ZZ

Why in-browser and BigInt matter

Two things make this converter dependable. First, it uses BigInt arithmetic, so it converts numbers of any length exactly — a 200-digit binary string stays accurate where an ordinary calculator would round or overflow. Second, every calculation happens client-side in your browser: your numbers never travel to a server. That means it's private enough for internal identifiers, fast enough to update as you type, and usable offline once the page has loaded. If you type a character that isn't valid for the chosen from-base — a 2 in a binary number, or a G in hex — the tool flags it and lists the digits that are allowed, so you can correct the input rather than get a wrong answer.

Try the Number Base Converter — free and 100% in your browser.

FAQ

How do I convert binary to decimal step by step?

Set the from-base to 2 and the to-base to 10, then type your binary digits. Each digit represents a power of two doubling from right to left, and the converter sums those place values for you. For 1010 that's 8 + 0 + 2 + 0 = 10.

What's the highest base I can convert to?

Base 36. It uses all ten digits 0–9 plus every letter A–Z, giving 36 symbols in total. Anything higher would need characters beyond the standard alphanumeric set, so 36 is the practical ceiling this tool supports.

Why do I get an "invalid digit" message?

A character in your number isn't permitted in the from-base you selected — like the letter G in hexadecimal, which only goes up to F. The converter lists the valid digits for that base so you can fix the entry and try again.

Can it handle very large numbers accurately?

Yes. It uses BigInt, which represents integers of arbitrary length exactly, so long binary strings and large hex values convert without any rounding — something a standard floating-point calculator can't guarantee.

Related free tools

• Binary Calculator — do arithmetic directly in binary.
• Roman Numeral Converter — another way to write numbers.
• Scientific Calculator — for follow-up calculations.
• Rounding Calculator — round decimal results cleanly.

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