Tax-exclusive: tax = amount × rate. Tax-inclusive: base = amount ÷ (1 + rate). Enter an amount and rate, then pick whether tax is added on top or already included.
What is Sales Tax / GST Calculator?
A sales tax calculator works out the tax on a purchase and the total a customer pays. For ecommerce sellers it's a quick way to check pricing, quote all-in costs, and understand how tax affects perceived price.
How it works
Sales tax = price × tax rate. Total = price + sales tax. A $200 item at an 8% rate carries $16 in tax for a $216 total. Rates vary by state, county, and city, so the applicable rate depends on the buyer's location.
How to use this tool
Enter the price and the sales tax rate. The calculator returns the tax amount and the final total. Use it to quote accurate all-in prices or check your checkout's tax math.
Why it matters
Unexpected tax at checkout is a leading cause of cart abandonment. Knowing the all-in price helps you set expectations, design pricing, and decide whether to show tax-inclusive pricing in the first place.
Frequently asked questions
How do I calculate sales tax?
Multiply the price by the tax rate as a decimal. $50 at 7% is $50 × 0.07 = $3.50 tax, for a $53.50 total.
Why does sales tax vary?
Rates are set by state and often layered with county and city taxes, so the total rate depends on where the buyer is. Ecommerce sellers may owe tax based on the customer's location.
Should I include tax in my listed price?
It depends on your market and platform. Tax-inclusive pricing reduces checkout surprise but can make your headline price look higher — test what your audience prefers.