To calculate shipping and taxes, you will need to know the weight of the item, the shipping destination, and the shipping method. You can use an online shipping calculator, or your own calculations, to estimate these costs.
To calculate the weight of the item, find the weight in ounces or pounds and convert it to grams. Next, find the shipping destination by using the USPS website or another shipping calculator. Finally, determine the shipping method you will use. The three most common methods are first-class, ground, and express.
After you have all of this information, you can use an online shipping calculator to estimate the cost of shipping. Most shipping websites have a "Shipping Calculator" tab on their homepage. Simply enter in the weight of the item, the shipping destination, and the shipping method. The shipping calculator will then give you an estimate of the shipping cost.
If you want to calculate the taxes, you will need to know the tax rate for the state or country where the item is being shipped. The tax rate can be found on the IRS website. To calculate the taxes, multiply the tax rate by the purchase price of the item.