The reason I posted this was I was talking to another guy who said that you multiply the net profit desired by the actual costs of the job.

$237.79 x .20 = $47.56
$237.79 + $47.56 = $285.35

I told him the correct method would be to take the desired net profit percent subtract that from 100% and divide your actual costs by this percentage.

100% - 20% = 80%
$237.79 / .80 = $297.24

So I thought I would post it to see how others would calculate this.