Sales Tax Calculator
Two directions: add tax to a pre-tax price, or pull the tax out of a tax-included total (the one people always get wrong).
Add tax to a price
Tax amount
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Total with tax
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Remove tax from a total (reverse)
Pre-tax price
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Tax portion
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The reverse-tax trap
To remove 13% tax from a $113 total, you divide by 1.13 (giving $100) — you do not subtract 13% ($113 × 0.87 = $98.31, which is wrong). Subtracting the percentage applies it to the wrong base. This matters constantly for bookkeeping: receipts show tax-included totals, but your accounting records need the pre-tax amount and the tax as separate lines.
Common rates for reference
| Region | Tax | Typical rate |
|---|---|---|
| Canada (ON) | HST | 13% |
| Canada (AB) | GST only | 5% |
| Canada (BC) | GST + PST | 12% |
| US states | Sales tax | 0–~10% (state + local) |
| UK / EU | VAT | Mostly 17–27% (UK 20%) |
| Australia / NZ | GST | 10% / 15% |
Rates change and many places have exemptions (groceries, children's clothing, etc.) — always confirm the current rate for your jurisdiction and product category.
Frequently asked questions
How do I handle two stacked taxes (like GST + PST)?
If both apply to the pre-tax price (the normal case in Canada), just add the rates: 5% GST + 7% PST = enter 12%. Genuine tax-on-tax stacking is rare — Québec abolished it in 2013.
Should my small business charge sales tax?
Most jurisdictions have a registration threshold (e.g., $30,000/year revenue in Canada before GST/HST registration is mandatory). Below it, registration is optional; above it, you must register, charge, and remit. Check your local tax authority — thresholds and rules change.
Why does my receipt tax differ by a cent from this calculator?
Rounding. Registers compute tax per item and round each line, while this tool computes tax on the total. Both are legal; they occasionally differ by a cent or two.