How Sales Tax & VAT Work (with Examples)

Adding tax to a price

To add tax, multiply the net price by (1 + rate). A $100 item at 8% tax is 100 x 1.08 = $108, of which $8 is tax. The rate as a decimal (0.08) times the price gives the tax amount ($8) directly.

Backing tax out of a total

When a price already includes tax (common with VAT), divide by (1 + rate) to find the net. A EUR 120 total at 20% VAT is 120 / 1.20 = EUR 100 net, so EUR 20 is tax. A frequent mistake is taking 20% of the gross (EUR 24) — that overstates the tax, because the 20% was charged on the net, not the total.

Inclusive vs exclusive pricing

Tax-exclusive pricing (common in the US) shows the pre-tax price and adds tax at the register, so the amount you pay is higher than the shelf label. Tax-inclusive pricing (common with VAT in Europe) shows the final price, tax already included. Knowing which you are looking at prevents a surprise at checkout.

Discounts and tax together

Where both apply, the discount usually comes off first and tax is charged on the reduced price. A $200 item at 15% off is $170; add 8% tax and you pay 170 x 1.08 = $183.60. The Sales Tax Calculator adds or removes tax either way, and pairs with the Discount Calculator for a true final price.

Frequently asked questions

Is VAT the same as sales tax? Similar for a shopper, but VAT is collected at each stage of production, while US sales tax is charged once at the final sale.

How do I find the tax rate from a receipt? Divide the tax amount by the pre-tax subtotal. $8 tax on an $100 subtotal is an 8% rate.

Why does the same item cost more at the register in the US? Because the shelf price is usually tax-exclusive — the tax is added at checkout.