Please Help?

I'd like to add Tax 7% in the following code for the Total (Label1.Text) in a checkout ecommerce page, please help. Thanks.

(Total=Total amount+Tax7%+Shipping cost)

here's the code

Label1.Text = Convert.ToString(decimal.Parse(totalAmountLabel.Text) + ShoppingCartAccess.GetShippingCost(shippingSelection.SelectedValue));
...