You will probably have a good idea as to what you want your design to look like. In order to calculate the price of your patch you will need to know the embroidered coverage of your patch by using the chart below. Black and gray areas represent stitching while white areas represent twill.

Once you have determined the embroidered coverage, you then need to work out the patch size, which can be done using the diagram below [(Length + Width) ÷ 2 = Size]: