Sales Tax Calculator Guide: How Tax Is Added
销售税计算器指南：各州税率和 nexus 规则
Sales tax is a percentage added to most retail purchases. The exact rate depends on where you buy — in the US, it varies by state, county, and even city, and five states charge no sales tax at all. This guide explains how to add tax to a price and how to work backwards from a tax-included total.
Adding Tax to a Subtotal
- Subtotal — price before tax
- rate — sales tax rate as a decimal (7.5% = 0.075)
Tax amount = Subtotal × rate.
Example: a $100 item in a 7.5% area costs 100 × 1.075 = $107.50, of which $7.50 is tax.
Extracting Tax From a Total
If you only know the final (tax-included) price and need the pre-tax subtotal, divide instead of multiply:
This is useful for receipt reconciliation and accounting.
Example: a $107.50 total in a 7.5% area means the subtotal was 107.50 ÷ 1.075 = $100.00.
US State Sales Tax Varies Widely
- No state sales tax: Delaware, Montana, New Hampshire, Oregon, Alaska (though local taxes may apply).
- Highest state rates: California (7.25%), Indiana, Mississippi, Rhode Island, Tennessee (7%).
- Combined rate: many cities and counties add their own tax on top, so the real rate you pay can be 9–10%+ in places like Los Angeles or Chicago.
Groceries are tax-exempt or reduced-rate in many states; clothing is exempt in Pennsylvania, New York (under $110), and others. Always check local rules.
Put It Into Practice
Enter any subtotal and tax rate to see the tax amount and total, or toggle to reverse-extract the subtotal from a final price.
sales tax 是一种加在大多数零售购买上的百分比税费。具体税率取决于你在哪里购买——在美国，税率因州、县甚至城市而异，五个州完全不征收 sales tax。本指南将解释如何在价格上加税，以及如何从含税总价反推计算。
在小计上加税
- 小计 — 税前价格
- 税率 — sales tax 税率（小数形式，7.5% = 0.075）
税额 = 小计 × 税率。
示例：一件 $100 的商品，在税率为 7.5% 的地区，花费为 100 × 1.075 = $107.50，其中 $7.50 为税额。
从总价中反推税额
如果你只知道最终（含税）价格，需要计算税前小计，则用除法而非乘法：
这对收据核对和记账非常有用。
示例：在税率为 7.5% 的地区，总价 $107.50 意味着小计为 107.50 ÷ 1.075 = $100.00。
美国各州 sales tax 差异很大
- 无州 sales tax：特拉华州、蒙大拿州、新罕布什尔州、俄勒冈州、阿拉斯加州（但可能适用地方税）。
- 最高州税率：加利福尼亚州（7.25%）、印第安纳州、密西西比州、罗德岛州、田纳西州（7%）。
- 综合税率：许多城市和县在此基础上再加征自己的税，因此在洛杉矶或芝加哥等地，你实际支付的税率可能达到 9–10% 以上。
在许多州，杂货食品是 exempt 或适用较低税率的；在宾夕法尼亚州、纽约州（$110 以下）等地区，服装是 exempt 的。请务必查看当地规定。
付诸实践
输入任何小计和税率，查看税额和总价，或切换为反向模式从最终价格反推小计。