#!/usr/bin/env perl
use strict;
use warnings;
use 5.010;

my $power_data = `system_profiler SPPowerDataType`;
my ($volts) = $power_data =~ /Voltage.*: (.*)/;
my ($amps) = $power_data =~ /Amperage.*: (.*)/;

printf "%0.2f\n", $volts * $amps / 1000000;