Finance Calculator

GST Calculator workspace

This interactive finance module is built for quick scenario testing with validated inputs, polished summaries, and reusable calculation logic.

Showing a sample GST scenario. Switch between exclusive and inclusive modes to either add GST or remove it from a total.

Base amount

10,000.00

The amount before GST is applied.

GST amount

1,800.00

The tax portion calculated from the selected GST rate.

Total amount

11,800.00

The final amount after GST is included.

Mode summary

ModeGST added
GST rate18.00%

Use exclusive mode when you know the price before tax. Use inclusive mode when the listed amount already includes GST and you need the pre-tax split.

Example calculation

These examples show both adding GST to a base amount and extracting GST from an already tax-inclusive total.

Example 1

If a base amount is 10,000 and GST is 18%, the GST amount is 1,800 and the total becomes 11,800.

Example 2

If a total already includes 18% GST, inclusive mode separates the pre-tax amount from the tax portion.

GST Calculator FAQ

When should I use inclusive mode?

Use inclusive mode when the listed amount already includes GST and you need to find the pre-tax value and the tax component inside it.

When should I use exclusive mode?

Use exclusive mode when you know the base price before tax and want to add GST on top of it.

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