You can calculate the shipping fee either based on the number of books ordered or the total weight of the books. Calculate order quantity If you have used the Neartail templates to create your form, order quantity field is included by default. Otherwise, you can follow the instructions below to calculate the order quantity. In the Edit page, click on the Add field button > enter the title Order Quantity, select Textbox widget and click Create > Field settings page will be displayed > click Answer > enter the formula QUANTITY() in the Calculate option and click Save. Setup unit weight for each product You can set up the unit weight for the products. In the Neartail Edit page, click on the gear icon next to the product > Product settings page will be displayed > click Advanced > enable Shipping, enter the unit weight for the product and click Save. Repeat the steps for all the products. Calculate total weight In the Edit page, click on the Add field button > enter the title Total Weight, select Textbox widget and click Create > Field settings page will be displayed > click Answer > enter the formula WEIGHT() in the Calculate option and click Save. Calculate shipping fee In the Neartail Edit page, click on the Add price field button > select Delivery fee, click Next > select Custom calculation, click Next > Enter the one of the formula below and click Create. Fee based on order quantity IFS(Order Quantity >= 5, 21, Order Quantity >= 3, 14, Order Quantity >= 1, 7, 0) Fee based on order weight IFS(Total Weight >= 3, 21, Total Weight >= 2, 14, Total Weight >= 1, 7, 0) Calculate total amount In the Edit page, click on the Add price field button > select Net amount, click Next > select Standard calculation using NETTOTAL() formula, click Next > click Create. Please try this and confirm.