This depends on your own size, but generally five yards of fabric will suffice for most shapes and sizes. You’ll need around 2.5 yards for the dress and about 2 yards for the trousers. If you’ve any doubt, speak with your tailor before purchasing. It’s likely your tailor will be able to sell you fabric as well as make your item, but if there’s nothing there that you like, then your tailor can advise how much fabric to buy from a cloth showroom or market.