Sales Tax Calculator

To calculate sales tax from a pre-tax price, multiply the price by the tax rate expressed as a percentage divided by 100. For example, with a price of 120 and a rate of 8.25%, the tax is 120 × (8.25/100) = 9.90. Then add that tax to the pre-tax price to get the total after tax: 120 + 9.90 = 129.90. Mode A in this Sales Tax Calculator performs these steps and rounds the displayed values to your chosen decimals.

If you only know the total after tax and the sales tax rate, you can reverse the calculation by dividing the total by the multiplier (1 + Rate/100). For example, if the total is 215 and the rate is 10%, the multiplier is 1.10 and the pre-tax price is 215 ÷ 1.10 = 195.4545. The tax amount is then Total − PreTax. Mode B in this Sales Tax Calculator automates this reverse method and clearly shows the substituted formula using your latest inputs.

Receipts can differ slightly because of rounding rules and item-level taxation. Some systems calculate tax per line item and round each line, then sum the rounded values, while others compute tax on the subtotal and round once. Small differences also appear when discounts are applied before tax, after tax, or proportionally across items. In addition, certain products may be exempt or taxed at different rates. This Sales Tax Calculator keeps full precision internally and then rounds displayed results to your selected decimals to reduce unexpected drift.

Sales tax is typically added at the point of sale as a separate amount on top of the listed price, so you often see the tax line and the total on the receipt. VAT (value-added tax) is usually applied throughout the supply chain and is often included in the displayed price in many regions. Because of that, VAT-inclusive pricing can make totals feel “built in,” while sales tax can feel like an add-on at checkout. This Sales Tax Calculator focuses on sales tax style calculations: pre-tax price, rate, tax amount, and total after tax.

Enter the rate that applies to your purchase in percent form, such as 6.5, 8.25, or 10. If your receipt shows a rate, use that value. If you’re estimating, use the local rate for where the purchase is taxed, which may depend on jurisdiction rules and whether shipping location affects taxation for online orders. If you’re comparing scenarios, keep the rate consistent across calculations so you can isolate the price difference. The calculator also caps unusually high values to prevent accidental inputs like 825 instead of 8.25.

In most cases, you should avoid rounding until the final step, because early rounding can compound small errors. Many receipts show tax rounded to two decimals because currency is typically displayed that way, but the underlying computation can involve more precision. This calculator keeps full precision internally, then rounds the displayed tax and total to your selected decimals. If you need to match a specific receipt, try the same decimal setting and remember that some receipts round per item rather than on the subtotal.

Yes. If the sales tax rate is 0%, the tax amount is 0 and the total equals the pre-tax price. A tax amount can also be effectively zero if a rate is extremely small and rounding to few decimals pushes it down to 0.00. Additionally, some products or transactions may be exempt from sales tax, even in locations where sales tax exists. This calculator does not determine exemptions; it simply applies the rate you enter. If you suspect exemption, set the rate to 0 or use the applicable reduced rate if you know it.

Discounts can change the taxable base depending on how the discount is applied. If a discount reduces the pre-tax price before tax, the tax amount is computed on the discounted price, lowering both tax and total. Some receipts apply coupons or promotions differently across items, which can change the item-level taxable amounts. For accurate checking, use the pre-tax subtotal that the receipt treats as taxable and apply the same rate shown on the receipt. You can use Mode A for pre-tax-to-total math or Mode B to back into the pre-tax base from a final total.