Hello there, @roxannatuttle116. Calculating taxes in QuickBooks Online (QBO) is easy. I'd be glad to share information about this.
In QBO, the total tax rate for each or your sale is automatically calculated based on the following:
Your customer's tax status
Where you sell and where you ship
What you sell
To further understand sales taxes and how to use it, feel free to check this sales tax guide. You can also reach out to your accountant or visit your state's sales tax website.
You'll also want to use the Sales tax calculator to easily determine the sales tax rate in your area. To get started, simply enter your business address and ZIP code.