Writing this math problem correctly?

[brianb]

hello,

I'm having a small issue with a math problem I'm trying to write in PHP...

Any help formatting this thing right is greatly appreciated!

$price_mw
divided by
$price_retail
minus 1
multiplied by 100
rounded up to the nearest full number

Thanks in advance!

[Moonglobe]

ceil((($price_mw /  $price_retail) - 1) * 100);