The basic shape
Tax is typically a percent of a taxable subtotal. Whether tax applies before or after coupons depends on law and retailer practice—when in doubt, check the receipt line items.
Why your mental math drifts
Rounding on each line vs once at the end, mixed rates for different categories, and “tax-inclusive” pricing abroad all change what you feel at the register.
Estimation habit
For quick estimates, round the subtotal, apply the rate, then add a small buffer for local add-ons. Precise planning for large purchases deserves a calculator run.
Use the calculator
FAQ
- Is sales tax the same as VAT?
Conceptually similar—a consumption tax—but VAT is often embedded in displayed prices and has different invoicing mechanics. Use jurisdiction-specific tools for accuracy.