Add tax or take it out
If you have a net price and need the total, answer No to "Does the price already include tax?" and the calculator adds the tax. If you have a final price and need to know how much of it is tax, answer Yes and it separates the two parts. In both cases you see three figures: before tax, tax and with tax.
Taking tax out of a price is where most people make mistakes. If 121 includes 21% VAT, the price before tax is 100, because the 21% was calculated on 100. Subtracting 21% of 121 would give a wrong figure. The calculator divides correctly, so the lines of an invoice add up.
Rates included and your own rate
The list includes the standard rates of Mexico (VAT 16%), Colombia (VAT 19%), Spain (VAT 21%), Portugal (VAT 23%), Argentina (VAT 21%), Chile (VAT 19%) and Peru (IGV 18%). These are general rates: many countries apply reduced rates to certain goods and services, and some products are exempt, so check the rate that applies to what you sell.
For any other rate, choose "Other rate" and type the percentage. That covers other countries, reduced rates and any tax that works as a percentage of the price.
US sales tax
The United States has no national VAT. Sales tax is set by each state, and counties and cities often add their own, so the combined rate depends on where the sale takes place, and some states have no sales tax at all. Look up the combined rate for your location and enter it as "Other rate".
Once entered, the calculator works the same way: add sales tax to a shelf price to know what you will pay at the register, or take it out of a receipt total to see the price before tax for your expense report.
Invoices, quotes and price lists
Freelancers use it to turn a fee into an invoice total, small shops to set shelf prices that already include tax, and employees to split the tax out of receipts for expense reports. It is also useful to compare a supplier quote shown before tax with a store price shown with tax.
Everything is calculated in your browser, so your amounts are not sent anywhere. It is free, with no account. For other percentage calculations, such as discounts or percentage change, use Percentage calculator, and to write an amount in words on an invoice, Number to words. Your accountant or tax authority has the final word on which rate applies.