Introduction
When you buy something, the receipt shows the total price you paid — but how much of that was tax? Our Reverse Tax Calculator helps you find the original price before tax was added. Just enter the total amount you paid and the tax rate, and this tool will split the number into two parts: the base price and the tax amount. It works for any sales tax rate in any state or country. Whether you need it for budgeting, bookkeeping, or filing expenses, this calculator gives you a clear answer in seconds — with a full step-by-step breakdown so you can see exactly how the math works.
How to Use Our Reverse Tax Calculator
Enter the total amount you paid and the tax rate to find out the original price before tax, the tax amount, and a full breakdown of your purchase.
Total Price (Including Tax): Type in the full amount you paid at checkout. This is the final price that already has tax added in.
Sales Tax Rate (%): Enter the tax rate that was applied to your purchase. For example, if your state charges 8% sales tax, type 8.
Click the Calculate button to see your results. The calculator will show you the original price before tax, the exact tax amount, a detailed breakdown table, a chart, and step-by-step math.
What Is a Reverse Tax Calculator?
A reverse tax calculator helps you find the original price of an item before tax was added. When you buy something at a store, the receipt shows the total price you paid, which includes sales tax. But sometimes you need to know how much the item cost before the tax was added. This calculator does that math for you. If you already know the base price and want to calculate the tax going forward, try our Sales Tax Calculator instead.
How Does It Work?
The calculator takes two numbers from you: the total price you paid and the sales tax rate. It then divides the total price by 1 plus the tax rate to find the original price. After that, it subtracts the original price from the total to show you exactly how much of your payment went to tax. This is essentially a percentage calculation in reverse — instead of adding a percent on top, you are working backward to remove it.
When Would You Use This?
You might need a reverse tax calculator when filing business expenses, doing bookkeeping, or checking if a store charged you the right amount of tax. It is also helpful when you want to compare the base price of products bought in different states or countries with different tax rates. Freelancers and small business owners use it often to separate tax from their purchase receipts. If you are working on broader tax planning, our Tax Bracket Calculator and Income Tax Calculator can help you understand your overall tax obligations. For those tracking business profitability after expenses and taxes, the Margin Calculator and Markup Calculator are also useful companions. And if you want to understand how much of your paycheck you actually keep, check out our Take Home Pay Calculator.
The Formula Behind the Calculation
The formula is simple. To find the original price, divide the total price by (1 + tax rate ÷ 100). For example, if you paid $108 and the tax rate is 8%, you divide $108 by 1.08. That gives you $100 as the original price and $8 as the tax amount. This works for any tax rate and any total price. If you want to see how percentages work in other contexts — such as finding the percent change between two values or calculating a discount on a purchase — we have dedicated tools for those as well. For related tax scenarios, our Self Employment Tax Calculator, Capital Gains Tax Calculator, Property Tax Calculator, and Payroll Tax Calculator can help you navigate different types of taxes you may encounter.