Sales Tax & VAT Calculator
Forward and reverse tax calculation
Choose whether the amount includes tax
Result
Calculation summary
Enter values to see the result
Tax composition preview
Net price and tax-inclusive total
Formula
gross = net × (1 + tax rate ÷ 100)
- Amount excluding tax
- $100.00
- Tax amount
- $8.25
- Total including tax
- $108.25
How to use this calculator
- 1Choose whether the entered amount excludes tax or already includes tax.
- 2Enter the amount, the applicable rate, and a display currency.
- 3Calculate the net amount, tax amount, and tax-inclusive total.
Formula
Gross = net × (1 + rate); net = gross ÷ (1 + rate)
Adding tax multiplies the taxable amount by one plus the rate. Extracting included tax reverses that multiplication.
Calculation steps
- Convert the entered rate from a percentage to a decimal.
- Multiply a net amount to add tax, or divide a gross amount to remove included tax.
- Find the tax amount as the difference between gross and net values.
Worked example
At 20% VAT, a net price of 100 becomes 120 gross. Reversing 120 ÷ 1.20 returns 100 net and 20 VAT.
Assumptions
- The calculator uses only the rate entered by the user and does not determine the applicable jurisdiction or product treatment.
- One rate applies to the complete amount.
- Displayed currency rounding may differ from invoice line-by-line or authority-specific rounding.
- Changing currency changes formatting only and does not convert amounts.
Sources
Frequently asked questions
How do I remove tax from an inclusive price?
Choose the tax-inclusive mode. The total is divided by one plus the tax rate; simply subtracting the percentage would be incorrect.
Why is tax not the same percentage of the gross total?
The stated rate applies to the net taxable amount. Tax is therefore a smaller percentage of the tax-inclusive gross amount.
Does the calculator select a local tax rate?
No. You must enter the rate that applies to the transaction.
Can invoice totals differ slightly?
Yes. Authorities and invoicing systems may round each line, each tax component, or the final total differently.