Add tax to a price, or work backward from a total to find the pre-tax price.
Adding tax: total = price × (1 + tax rate). Removing tax: pre-tax price = total ÷ (1 + tax rate). Useful for pricing products, checking receipts, or reconciling invoices across states with different sales tax rates.
If your business has "nexus" in a state — a physical presence, employees, or enough sales volume — you may be required to collect and remit sales tax there, even if you're not physically located in that state. Rules vary significantly by state.
Use "add tax to price" when pricing a product before checkout. Use "remove tax from total" when you have a receipt or final charge and need to reconstruct the pre-tax price — common when reconciling expenses or checking a vendor's math.
Sales tax isn't just a state-level number — many states layer county, city, and special district taxes on top of the state rate, so the effective rate can vary block to block in some areas. If you sell to customers in multiple states or municipalities, checking the current combined rate for each specific location (rather than assuming one flat state rate) avoids under- or over-charging tax.
Do all states have the same sales tax rate? No — rates vary by state, and many states also add county or city-level tax on top, meaning the effective rate can differ block to block in some areas. Always confirm the local combined rate.
Are services taxed the same as goods? Not usually. Many states tax physical goods but exempt most services, though this varies significantly. Check your state's specific rules for your type of business.
What if I sell in multiple states? You may need to register, collect, and remit sales tax separately in each state where you have nexus. This can get complex fast — many multi-state sellers use dedicated sales tax software once volume grows.