Sales Tax Calculator
Calculate tax amount and total price or reverse tax from gross.
$
Original sticker or catalog price
%
Presets:
%
Optional county/district surcharge
Total with Sales Tax
$108.25
$100.00 + 8.25% tax ($8.25) = $108.25 total
Sales Tax Amount$8.25
Combined Tax Rate8.25%
Pre-Tax Subtotal$100.00
Tax Rate Breakdown:
Combined sales tax rate is 8.25% (8.25% state base). On an amount of $100.00, the tax component equals $8.25.
How It Works
The Sales Tax Calculator computes total retail prices including state and local sales taxes, or reverses a tax-inclusive receipt total to determine the original pre-tax price.
It handles combined state, county, and municipal tax rates with exact penny rounding.
Formula & Calculation
Adding Sales Tax Formula
Total Price = Pre-tax Amount × (1 + (TaxRate / 100))
Pre-tax Amount=Item list price before tax
TaxRate=Combined sales tax percentage
Tax Amount=Pre-tax Amount × (TaxRate / 100)
Reverse Sales Tax Formula
Pre-tax Price = Total Price / (1 + (TaxRate / 100))
Total Price=Final receipt charge
TaxRate=Sales tax percentage rate
Tax Amount=Total Price − Pre-tax Price
Step-by-Step Example
Example: Adding 8.25% Sales Tax to a $100 Purchase
Calculating tax on a retail purchase:
Step 1: Calculate tax portion:
$100.00 × 0.0825→ $8.25 taxStep 2: Add tax to subtotal:
$100.00 + $8.25→ $108.25 total dueThe total register price is $108.25 ($8.25 sales tax).
Assumptions & Edge Cases
- Combined Jurisdiction Rates: In the US, state, county, and city sales taxes are combined into a single additive rate applied to the taxable subtotal.
Frequently Asked Questions
Which US states do not have a statewide sales tax?
Alaska, Delaware, Montana, New Hampshire, and Oregon do not levy statewide sales taxes (though some Alaska municipalities levy local sales taxes).