I've noticed there's a grey area in tipping. If you order delivery, do you tip a percentage of the subtotal of all the food or do you also include the delivery fee? For example, you order a sandwich and drink, which costs: $22.50 (food and drink) $3.00 (delivery fee). $2.14 (tax) I know you don't include the tax. However, if you want to tip 20%, do you calculate $22.50 X .20? Or do you add the delivery fee and thus calculate $25.50 X .20?