Sales Tax Calculator
Add sales tax to a price or work backwards from a tax-inclusive total to find the pre-tax amount and the exact tax paid.
Como usar esta calculadora
- 1Choose whether you are adding tax to a price or removing it from a total.
- 2Enter the amount — the pre-tax price when adding, the tax-inclusive total when removing.
- 3Enter your combined sales tax rate. Check your state and local rate for the delivery address.
- 4Set a quantity if you are pricing more than one of the same item.
Como funciona
Sales tax formulas
Adding tax: total = price × (1 + rate)
tax = price × rate
Removing tax: price = total ÷ (1 + rate)
tax = total − priceAdding tax is a simple multiplication. Removing it is not a subtraction: because the tax was charged on the pre-tax price, you have to divide the total by one plus the rate to recover it. Subtracting 8.25% from a tax-inclusive total gives a number that is too small, and the error grows with the rate.
Exemplo resolvido
A $129.99 item at an 8.25% rate costs $10.72 in tax for a total of $140.71. Working backwards from a $140.71 receipt: $140.71 ÷ 1.0825 = $129.99 before tax, confirming $10.72 of tax.
Sales Tax Calculator: o guia completo
Reverse sales tax: the mistake almost everyone makes
Given a $140.71 receipt at an 8.25% rate, the instinct is to subtract 8.25% of $140.71 — which gives $129.10. That is wrong by 89 cents, because the tax was never charged on $140.71. It was charged on the smaller pre-tax price.
The correct operation is division: $140.71 ÷ 1.0825 = $129.99. This matters for expense reports, VAT-style reclaims, and anyone splitting a tax-inclusive invoice into net and tax lines. The higher the rate, the larger the error from subtracting instead of dividing.
Why your rate is not just the state rate
In the United States, the rate you actually pay is a stack: a statewide base rate plus county, city, and sometimes special-purpose district rates for transit or stadiums. Two addresses a mile apart can carry different combined rates, and the applicable rate is generally determined by where the buyer takes delivery, not where the seller is located.
Five states — Alaska, Delaware, Montana, New Hampshire, and Oregon — have no statewide sales tax, though Alaska allows local sales taxes. For online orders, economic nexus rules mean most sellers now collect tax based on the shipping destination.
Exemptions and reduced rates
Most states tax tangible goods but exempt or reduce the rate on necessities. Groceries, prescription drugs, and medical devices are the most common exemptions; clothing is exempt or capped in a handful of states. Services are frequently untaxed, though the list of taxable services has been expanding.
Because these categories vary so much, enter the effective rate for the specific item rather than assuming the general rate applies to the whole basket.
Perguntas frequentes
How do I find the pre-tax price from a receipt total?
Divide the total by one plus the tax rate expressed as a decimal. For an 8.25% rate, divide by 1.0825. Switch this calculator to "Remove tax from a total" and it does exactly that.
Is sales tax the same as VAT or GST?
They serve the same purpose but work differently. US sales tax is charged once, at the final retail sale. VAT and GST are charged at each stage of production with businesses reclaiming the tax they paid, and prices are usually quoted tax-inclusive. The reverse-tax mode here works for VAT-inclusive prices too.
What rate should I enter?
Your combined rate — state plus county plus city plus any district taxes — for the address where the goods are delivered. State revenue department websites publish lookup tools by ZIP code or full address.
Is sales tax applied before or after a discount?
After. A store discount reduces the taxable price, so tax is charged on what you actually pay. Manufacturer coupons are treated differently in some states, where tax may still apply to the pre-coupon price.