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GoProOffice

No. 16Operations & People

Sales Tax Calculator

Add sales tax to a pre-tax price, or work backward from a tax-inclusive total to find the original price and the tax paid.

Calculation

Combined state + local rate for the place of sale.

Results

Total with tax

$108.25

  • Price before tax
  • Sales tax
Sales tax
$8.25
Price before tax
$100.00

A mathematical estimate using the rate you entered. It doesn’t determine which rate or exemptions apply to a sale.

Show the calculation
  1. Sales tax$100.00 × 8.25%= $8.25
  2. Total$100.00 + $8.25= $108.25

How it’s calculated

Adding tax

Sales Tax
equals Price × (Rate ÷ 100)
Total
equals Price + Sales Tax

Removing tax from a total

Pre-tax Price
equals Total ÷ (1 + Rate ÷ 100)
Sales Tax
equals Total − Pre-tax Price

To remove tax, divide by (1 + rate) — don’t subtract the rate from the total. Subtracting 7% from a $107 total gives $99.51, not the correct $100.

Worked example

Two everyday cases:

  1. Invoicing $1,250 of goods at a 7.25% rate: tax = $90.63, total = $1,340.63
  2. A receipt shows $53.50 including 7% tax: pre-tax price = $53.50 ÷ 1.07 = $50.00, tax = $3.50

Assumptions and limitations

  • You must supply the rate. The calculator doesn’t look up rates by address, and combined state, county, city and district rates vary widely.
  • Tax is rounded to the nearest cent on the total amount. Some systems round per line item, which can differ by a cent.
  • Whether a sale is taxable at all depends on the product, the buyer and the jurisdiction (exemptions, resale certificates, digital goods rules). This tool doesn’t make that determination.

Results are estimates for information only and are not financial, tax or legal advice. See our disclaimer.