Math & Scientific
Number Base Converter
Number Base — it converts a number between bases by expanding it as a sum of digit × base^position, then re-expressing it in the target base. This page runs that same calculation on your numbers, in your browser: no signup, no uploads, nothing stored.
Use Number Base Converter to work through a calculation: give it your number, from base and to base, press Calculate, and read off the result — all worked out on your device.
About this calculator
Get number base right and the rest of the task gets easier. It converts a number between bases by expanding it as a sum of digit × base^position, then re-expressing it in the target base. It matters when you need the exact relationship checked quickly rather than worked through by hand. Convert decimal 42 to binary: 42 = 32 + 8 + 2 = 101010₂ (and 2A in hexadecimal). The tool above does the same computation in your browser — free, private, nothing stored.
How to use
- Enter the number to convert.
- Set the From base (2 to 36).
- Set the To base (2 to 36).
- Press Calculate to see the result.
Why use Number Base Converter
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Accurate
Conversions are computed exactly in your browser, with no rounding beyond what is shown.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Honest disclaimers wherever browser limits or regional rules apply.
Common uses
Use it when revising for exams
Use it when preparing worksheets
Use it for verifying answers from a textbook
Number Base in competitive-exam practice
Use it for quick mental-math cross-checks
Use it when working through problems
Technical notes
Number Base Converter converts a number between bases by expanding it as a sum of digit × base^position, then re-expressing it in the target base.
Inputs are taken exactly as entered, so check for typos before trusting an answer.
Because it runs locally, results appear instantly with no server round-trip.
FAQ
What bases are supported?
Any whole-number base from 2 to 36, using digits 0–9 and letters A–Z.
What happens with an invalid digit?
A digit too large for the source base, like a 2 in base 2, is rejected rather than partially parsed.
Does it handle very large numbers?
Yes. Conversion uses big-integer arithmetic, so large values stay exact.
Does the Number Base Converter send my data to a server?
No. The Number Base Converter runs entirely in your browser, so nothing you enter is uploaded, stored, or shared.
Worked example
Convert decimal 42 to binary: 42 = 32 + 8 + 2 = 101010₂ (and 2A in hexadecimal).