How do I get the size of a file in megabytes using Perl

my $size_in_mb = (-s $fh) / (1024 * 1024);

use Number::Bytes::Human qw(format_bytes);
my $size = format_bytes(-s $file); # 4.5M

sub size_in_mb {
    my $size_in_bytes = shift;
    return $size_in_bytes / (1024 * 1024);
}

my $size_in_mb = (-s $fh) / (1024 * 1024);