Finance

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GST Calculator.

Calculate Goods and Services Tax (GST) easily, with support for standard slab rates and localized splitting.

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Results update as you type.

Calculation Result

Net Price (Pre-Tax)

1,000.00

GST Tax Amount

180.00

Gross Price (Post-Tax)

1,180.00

Indian GST Split (For Intra-State Transactions)

CGST (Central Tax - 50%)

90.00

SGST (State Tax - 50%)

90.00

IGST (Integrated Tax - 100%)

180.00

FAQs

What is GST?

GST (Goods and Services Tax) is an indirect tax levied on the supply of goods and services. It replaces multiple nested taxes in countries like India, Australia, and Canada.

How is GST calculated?

To add GST: Gross = Net × (1 + Rate/100). To remove GST: Net = Gross / (1 + Rate/100).

What is the difference between CGST, SGST, and IGST?

CGST (Central GST) and SGST (State GST) are levied on intra-state supplies, each representing 50% of the total GST rate. IGST (Integrated GST) is levied on inter-state transactions and is equal to the total GST rate.

What are the common GST slabs?

Common GST slabs in India are 5%, 12%, 18%, and 28%. In Australia, it is a flat 10%, and in Canada, a flat 5% federal rate applies.

Cite this calculator

Canonical URL: https://mathify.one/en/finance/gst

Cite as: Mathify. (2026). GST Calculator. https://mathify.one/en/finance/gst

Use Cases

Retail Pricing

Determine the final selling price by adding GST to your wholesale or cost price, ensuring you cover the tax.

Example: Add 10% GST to a $100 product to get a total of $110.

Invoice Reconciliation

Extract the pre-tax amount from a total invoice to verify charges or claim input tax credits.

Example: Remove 18% GST from a $1,180 invoice to find the base amount of $1,000.

Frequently Asked Questions

How do I add GST to a price?
Enter the base price (excluding GST) and select your GST rate. The calculator will show the GST amount and the total price including GST.
How do I remove GST from a price?
Enter the total price (including GST) and select the GST rate. The calculator will show the pre-GST price and the GST amount included.
Can I use a custom GST rate?
Yes, you can enter any custom GST rate percentage to match your specific tax jurisdiction or product category.

Tips & Common Mistakes

Tips

  • Always double-check the GST rate for your country or region, as it can vary (e.g., 5%, 10%, 12.5%, 20%).
  • When adding GST, multiply the base price by (1 + rate/100). For removing, divide the total by (1 + rate/100).
  • Use the custom rate option for special cases like reduced rates on certain goods or services.
  • Keep a record of your calculations for accounting and tax filing purposes.

Common Mistakes to Avoid

  • Confusing the base price with the total price when adding or removing GST, leading to incorrect results.
  • Using the wrong GST rate, especially when a custom rate is needed for a specific product or service.
  • Forgetting to round the final amount to the nearest cent, which can cause discrepancies in invoices.

Last updated: August 13, 2026