How do I use the sales tax calculator?

Enter any two of the three values: pre-tax price, sales tax amount, or final price. The calculator will compute the missing value. For example, enter the pre-tax price and the sales tax rate to get the tax amount and final price.

Can I calculate the pre-tax price from the final price?

Yes. Enter the final price and the sales tax rate (or tax amount) to find the pre-tax price. The calculator will reverse the tax addition to give you the original amount before tax.

What if I only know the sales tax rate and the final price?

You can still use the calculator. Enter the final price and the tax rate (as a percentage) to find the pre-tax price and the tax amount. The calculator handles the math for you.

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增值税 / 销售税.

2026年8月4日

计算含税和不含税价格

此计算器尚未完全翻译——部分文本以英文显示。

设备端计算无需注册

输入数值

输入时结果会更新。

02 / 答案

税率预设

净价（$）

税率（%）

净价

US$100.00

税前

税额

US$10.00

10% 税额

含税价

US$110.00

含税

明细:

净价: $100.00

税额 (10%): $10.00

含税价: $110.00

使用方法

加税: 当你有税前价格并想得到最终含税价格时使用。

去税: 当价格已含税并需要税前基价时使用。

常见错误: 不要从含税价中直接减去税率百分比。必须除以 (1 + 税率)。

Cite this calculator

Canonical URL: https://mathify.one/zh/finance/sales-tax

Updated 2026年8月4日

Cite as: Mathify. (2026). 增值税 / 销售税. https://mathify.one/zh/finance/sales-tax

Use Cases

Budgeting for a purchase

Determine the total cost including sales tax before you go to the store or make an online purchase, so you can plan your spending accurately.

Example: You want to buy a $500 laptop and your local sales tax is 8%. The calculator shows you'll pay $540 in total.

Checking a receipt

Verify that the sales tax charged on a receipt is correct by entering the pre-tax price and the tax rate, or by entering the final price and tax amount to find the pre-tax price.

Example: Your receipt shows a final price of $107.50 with a 7.5% tax rate. The calculator confirms the pre-tax price was $100.

Frequently Asked Questions

How do I use the sales tax calculator?: Enter any two of the three values: pre-tax price, sales tax amount, or final price. The calculator will compute the missing value. For example, enter the pre-tax price and the sales tax rate to get the tax amount and final price.
Can I calculate the pre-tax price from the final price?: Yes. Enter the final price and the sales tax rate (or tax amount) to find the pre-tax price. The calculator will reverse the tax addition to give you the original amount before tax.
What if I only know the sales tax rate and the final price?: You can still use the calculator. Enter the final price and the tax rate (as a percentage) to find the pre-tax price and the tax amount. The calculator handles the math for you.

Tips & Common Mistakes

Tips

Always enter the sales tax rate as a percentage (e.g., 8 for 8%), not as a decimal (0.08).
If you know the tax amount but not the rate, you can enter the pre-tax price and the tax amount to find the rate.
Double-check that you are using the correct tax rate for your location, as rates can vary by city, county, and state.
Use the calculator to compare prices across different tax jurisdictions to see the true cost difference.

Common Mistakes to Avoid

Entering the tax rate as a decimal instead of a percentage (e.g., 0.08 instead of 8) leads to incorrect results.
Confusing the pre-tax price with the final price when entering values, especially when you have a receipt that shows the total.
Forgetting that some items are tax-exempt; the calculator assumes a uniform tax rate, so adjust for exempt items manually.

Last updated: August 13, 2026