Sales Tax Calculator
Add sales tax to a price, or work out the tax already included in a total.
Per-item net
$100.00
Per-item tax
$8.25
Per-item gross
$108.25
Total net
$100.00
Total tax
$8.25
Total gross
$108.25
How to use Sales Tax Calculator
- 01Enter the price and your tax rate.
- 02Choose whether the price excludes tax (add it) or already includes tax (extract it).
- 03Set a quantity if you need the total for several items.
About Sales Tax Calculator
Adding tax is straightforward: multiply the net price by one plus the rate. Working backwards is where people go wrong — you cannot subtract the percentage from the gross. To find the tax inside a total, divide by one plus the rate to get the net, then subtract.
At an 8% rate, a $108 gross price contains $8 of tax, not $8.64. The difference looks small on one item and becomes significant across an invoice, which is why reverse calculation matters for anyone reclaiming tax or reconciling receipts.
Frequently asked questions
- How do I remove tax from a total?
- Divide the total by 1 plus the rate. The calculator's extract mode does it for you.
- Does it work for VAT or GST?
- Yes, the maths is identical — just enter your local rate.
- Are local rates included?
- No, rates vary by city and county, so enter the combined rate that applies to you.
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