Total tax

Combined rate
Taxable amount
Order total
State portion
County & city portion

How it works

Sales tax in layered systems is charged by several authorities at once, each with its own rate on the same base. Because they all apply to the pre-tax price rather than compounding on one another, the rates simply add together into a single combined rate.

That additivity is what makes the combined figure straightforward — but it also means a small city rate on top of a state rate can push the total well past what a customer expects from the headline number alone.

Combined rate = state + county + city · Tax = subtotal × combined rate

  • Subtotal — the pre-tax total of all line items
  • Combined rate — the sum of every applicable jurisdiction’s rate
  • Exempt amount — the portion of the order not subject to tax

Worked example

A 12,400 order with 6.25% state, 1.75% county and 1% city tax, and 1,200 exempt

Inputs

Subtotal12,400
Exempt1,200
Rates6.25 + 1.75 + 1

Results

Total tax1,008.00
Combined rate9.00%
Order total13,408.00

The headline state rate is 6.25%, but the customer pays 9%. On this order the local layers add 336.

Frequently asked questions

Do the rates compound?

No. Each authority charges on the pre-tax price, so the rates add rather than stack. A 6% and a 3% rate produce 9% tax, not 9.18%.

What counts as exempt?

It varies widely — often unprepared food, prescription medicines, and sales to resellers or exempt organisations. Enter the exempt portion of the order and the tax is charged only on the balance.

Which jurisdiction’s rate applies?

In most destination-based systems, the buyer’s location rather than the seller’s. That is why a business shipping nationally can face hundreds of distinct combined rates.

Is my data sent anywhere?

No. The calculation runs entirely in your browser. Nothing you type is transmitted to us or stored.

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