1. What is Reverse GST Calculation?

Reverse GST calculation is used to determine the original amount before GST was added when you only know the total amount including GST. This is particularly useful in accounting and when dealing with receipts that show only the total amount paid.

2. How Does the Calculator Work?

The calculator uses the reverse GST formula:

Where:

• \( Amount \) — Total amount including GST (in CAD)
• \( GST \) — GST rate as a decimal (e.g. 0.05 for 5%)

Explanation: The formula works by dividing the total amount by (1 + GST rate) to find the original amount before GST was added.

3. When to Use Reverse GST Calculation

Details: This calculation is essential when you need to:

• Separate GST from a total amount on a receipt
• Calculate business expenses for tax purposes
• Determine the pre-tax value of goods or services
• Verify GST amounts on invoices

4. Using the Calculator

Tips:

• Enter the total amount in Canadian dollars (CAD)
• Enter the GST rate as a decimal (e.g. 0.05 for 5%)
• All values must be positive numbers
• The calculator automatically rounds to 2 decimal places

5. Frequently Asked Questions (FAQ)

Q1: Why use reverse GST calculation?
A: It helps determine the original price before tax was added, which is important for accounting, expense tracking, and tax reporting.

Q2: Does this calculator work for HST?
A: Yes, if you're in a province with HST, you can use the combined HST rate in the GST field.

Q3: What if I need to calculate with PST?
A: This calculator is for GST-only calculations. For PST-inclusive calculations, you would need a different formula.

Q4: How accurate is this calculation?
A: The calculation is mathematically precise, but always verify with official tax guidelines for your specific situation.

Q5: Can I use this for multiple GST rates?
A: The calculator handles one GST rate at a time. For multiple rates, you would need to perform separate calculations.