Sales Tax Calculator
Add sales tax to a price, or work out the pre-tax price from a tax-inclusive total.
Every calculation runs locally in your browser. Nothing you enter here is sent to a server or stored anywhere.
Pre-tax amount
$50
Tax amount
$4
Total
$54
For informational and educational purposes only — not financial, investment, or tax advice, and not a substitute for consulting a qualified professional about your specific situation. TrueMeasureKit is not liable for decisions made based on these results. See our Terms of Service.
Why "extract" isn't just dividing by the rate
A common mistake: given a $108 total at 8% tax, it's tempting to compute tax as 8% of $108 ($8.64) — but that overstates it, because the $108 already includes tax on top of a smaller base price. The correct approach divides the total by 1 + rate to recover the pre-tax amount first ($108 / 1.08 = $100), then the tax is the difference ($8). This calculator's "extract" mode does that division for you automatically.
Frequently asked questions
How do I find the pre-tax price from a tax-inclusive total?
Switch to reverse mode: divide the tax-inclusive total by (1 + tax rate) to back out the pre-tax price — useful when a receipt only shows the final amount and you need the subtotal.
Does this calculator know my local sales tax rate?
No — sales tax rates vary by state, county, and even city, so you enter the rate yourself. Check your local government or retailer receipt for the exact combined rate.