The London Perl and Raku Workshop takes place on 26th Oct 2024. If your company depends on Perl, please consider sponsoring and/or attending.


Math::Int2Base - Perl extension for converting decimal (base-10) integers into another number base from base-2 to base-62, and back to decimal.


  use Math::Int2Base qw( int2base base2int base_chars );

  my $base = 16;  # i.e., hexidecimal
  my $hex = int2base( 255,  $base );  # FF
  my $dec = base2int( $hex, $base );  # 255

  my $sixdig = int2base( 100, 36, 6  ); # 00002S
  my $decno  = base2int( $sixdig, 36 ); # 100, i.e., leading zeros no problem

  my $chars = base_chars( 24 );  # 0123...KLMN
  my $regex = qr/^[$chars]$/;    # used as character class

  use bigint;  # if needed
  my $googol = 10**100;
  my $base62 = int2base( $googol, 62 );  # QCyvrY2MJnQFGlUHTCA95Xz8AHOrLuoIO0fuPkHHCcyXy9ytM5N1lqsa
  my $bigint = base2int( $base62, 62 );  # back to 1e+100

  # from one base to another (via base-10)
  sub base_convert {
      my( $num, $from_base, $to_base ) = @_;
      return int2base( base2int( $num, $from_base ), $to_base );


Math::Int2Base provides

  • int2base( $int, $base, $minlen ) for converting from decimal to another number base,

  • base2int( $num, $base ) for converting from another base to decimal, and

  • base_chars( $base ) for retrieving the string of characters used to represent digits in a number base.

This module only works with positive integers. Fractions are silently truncated to integers.


  • Only (so far) supports bases from 2 to 62

  • Does not (yet) support bases that skip digits (e.g., base-24 skips I and O, Math::Int2Base doesn't)

  • Only supports positive integers.

  • Does not support flexible case letters, e.g., in hexidecimal, F == f.

    In Math::Int2Base, f is not a hex digit, and A(base-16) == A(base-36) == A(base-62).

SEE ALSO Math::BaseCnv Math::BaseCalc

The code is based on newsgroup discussion particularly that of Dr. Ruud. Errors are my own.


Brad Baxter, <>


Copyright (C) 2010 by Brad Baxter

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available.