VAT / Sales Tax Guide: Add and Remove Tax Correctly
Add tax, extract tax from a gross amount and avoid percentage mistakes.
What it does and when to use it
Sales tax or VAT is calculated on the pre-tax price. If the total already includes tax, do not subtract the rate directly; divide by one plus the rate.
What information to enter
Enter amount and tax rate. Choose whether the amount is before tax or already tax-included.
How to understand the result
The result separates pre-tax price, tax amount and final price. This helps with invoices and price comparisons.
Recommended step-by-step workflow
- Check the assumptionsSales tax or VAT is calculated on the pre-tax price. If the total already includes tax, do not subtract the rate directly; divide by one plus the rate.
- Use matching unitsEnter amount and tax rate. Choose whether the amount is before tax or already tax-included.
- Compare with another scenarioThe result separates pre-tax price, tax amount and final price. This helps with invoices and price comparisons.
Formula at a glance
Short example
Why this matters
Sales tax or VAT is calculated on the pre-tax price. If the total already includes tax, do not subtract the rate directly; divide by one plus the rate.
Step by step
- Define exactly what you want to calculate and which unit is correct.
- Enter values as they appear on a document, receipt, payslip or real measurement.
- Compare at least one extra scenario to see whether the result is sensitive to small input changes.
Numeric example
₪118 including 18% VAT consists of ₪100 before VAT and ₪18 tax.
Mistakes to avoid
- Mixing numbers from different periods or units in one calculation.
- Ignoring assumptions, fees or limits the calculator cannot know by itself.
- Making a large decision from one result without testing a conservative scenario.
When to open the calculator
Open the calculator when you want to turn the explanation into a more exact number using your own inputs.
Common mistakes
- Mixing numbers from different periods or units in one calculation.
- Ignoring assumptions, fees or limits the calculator cannot know by itself.
Frequently Asked Questions
Is this a final answer?
Not always. It is a calculation or estimate based on the values entered.
What should I check before relying on it?
Check units, dates, fees and whether an important personal detail is missing.
Are my inputs saved?
No. The calculation runs in the browser and does not store your personal inputs.