Add GST to a pre-tax amount
Exclusive mode multiplies the base amount by the rate, then adds the tax to produce the total.
- Pre-tax base
- GST amount
- Inclusive total
Free business tool
See the pre-tax amount, GST component and total at a glance
Enter an amount and GST percentage, then specify whether tax is already included. The calculator handles both directions and keeps every part of the result visible.
- Inclusive or exclusive GST
- Transparent three-part breakdown
- No data submitted
Last updated:
Free browser tool
Calculate the GST breakdown
Use exclusive mode to add GST, or inclusive mode to extract the GST already present in a total.
Result
0.00- Base amount
- 0.00
- GST
- 0.00
- Total
- 0.00
GST systems differ by country and may use multiple components, exemptions or special rounding. Confirm the jurisdiction-specific rate and reporting treatment.
How to use it well
Make the inclusive-versus-exclusive choice explicit
A percentage cannot be interpreted correctly until you know whether the entered amount is before tax or already includes it.
Calculate in either direction
The same three values, with a different starting point.
Extract GST from an inclusive price
Inclusive mode divides by one plus the rate to recover the base, then shows the GST difference.
- Inclusive starting value
- Recovered base
- Extracted GST
Apply the correct context
Rate selection remains a business responsibility.
Check registration and supply rules
Applicable rates can depend on the supplier, customer, location, item category and transaction date.
- Registration status
- Supply location
- Item classification
Account for multi-part GST where relevant
Some systems split a total rate into central, state, provincial or harmonized components. This tool shows one combined rate.
- Combined rate only
- Local components may differ
- Confirm return treatment
Keep the evidence
A breakdown is more useful than a single final number.
Show the base and GST separately
Carry both values into the document or record so the tax basis remains understandable.
- Pre-tax amount
- GST amount
- Tax-inclusive total
Save recurring settings in Invoice Crowd
The calculator is intentionally temporary. The product workflow can keep taxes, customers and documents together.
- Reusable taxes
- Saved documents
- Customer records
Questions
GST Calculator, answered
How does the GST calculator work?
Enter an amount and GST rate. In exclusive mode the tax is added to the entered net amount. In inclusive mode the tax is extracted from the entered gross total.
How do I calculate tax from a GST-inclusive price?
Check Amount includes tax. The tool divides the gross amount by one plus the entered rate to calculate the base, then displays the tax difference.
Does the calculator choose the correct rate?
No. You provide the rate. Confirm the applicable percentage, exemptions, place-of-supply rules and transaction date for your jurisdiction.
How are decimals rounded?
The display rounds to two decimal places. Tax authorities or accounting policies may require different currency, line-level or document-level rounding.
Does this provide tax advice?
No. It is a general arithmetic tool. A qualified adviser or tax authority can confirm the treatment for a specific transaction.
Are my figures sent to Invoice Crowd?
No. The calculation runs locally in your browser and the entered figures are not submitted to Invoice Crowd.
Ready to keep the work, not just the calculation?
Use Invoice Crowd to save customers, products, taxes and business documents in one connected workspace.
- No card required to start
- Your records stay yours
- Cancel anytime