Sales Tax Calculator
It adds sales tax to a pre-tax price, or extracts the tax already baked into a total.
Total including tax
$267.50
Net
$250.00
Tax
$17.50
Gross
$267.50
What it calculates
It adds sales tax to a pre-tax price, or extracts the tax already baked into a total.
Why it matters
Getting tax-inclusive pricing wrong distorts invoices, margins and the sales tax you owe.
Who it's for
Shoppers checking a receipt, freelancers invoicing, and e-commerce sellers working across state rates.
Formula
- N
- Net price, excluding tax
- G
- Gross price, including tax
- t
- Tax rate
Worked example
$107.00 total at a 7% sales tax rate
- 1Pre-tax = 107 ÷ 1.07 = 100
- 2Tax = 107 − 100
Pre-tax price $100.00, sales tax $7.00
How the sales tax calculator works
Adding tax: G = N × (1 + t). Removing tax: N = G ÷ (1 + t). Never subtract the rate from a gross price — that under-states the net figure.
In add mode the amount you type is treated as the price before tax. In remove mode it is treated as the tax-inclusive price and the tax is extracted from it.
Reverse calculation is not simply subtracting the percentage — 20% VAT inside a gross price is one sixth of that price, not one fifth.
Common mistakes
- Subtracting the rate from a total instead of dividing by 1 plus the rate.
- Applying the standard rate to reduced or zero-rated goods.
- Forgetting that registration thresholds and rules differ by country.
Tips and best practice
- Store net prices in your records and derive gross at display time.
- Check reduced rates — food, books and children's items are often taxed differently.
Frequently asked questions
How do I work out the price before sales tax?
Divide the total by (1 + rate). At a 7% sales tax rate, divide by 1.07 to get the pre-tax price.
What is the difference between VAT and sales tax?
VAT is collected at each stage of the supply chain with credits for input tax; US sales tax is charged once at the final sale.
What sales tax rate should I use?
US sales tax is set by state and locality, so it varies from 0% in states like Oregon and Delaware to over 10% once city and county rates stack on top. Check the combined rate for the exact address.
Is VAT charged on shipping?
In most jurisdictions delivery charges follow the VAT treatment of the goods being shipped.
Related calculators
Further reading
Methodology & trust
- Formula source
- Standard VAT/sales tax arithmetic.
- Last updated
- 2026-07-28
- Privacy
- Every calculation runs in your browser. No inputs are sent to a server or stored.
- Accessibility
- Keyboard navigable, labeled inputs and WCAG AA color contrast.