GST Calculator
Add GST to a base price, or work out the base price and GST from a final amount.
Exclusive vs inclusive amounts
"Add GST" treats your amount as the base price and adds GST on top. "Remove GST" treats your amount as already including GST — common when a receipt only shows the final price — and works backward to find the base and tax split.
About the GST Calculator
The GST Calculator adds GST to an amount, or removes it from a GST-inclusive price to find the base amount and tax. It supports common rates such as 5, 12, 18 and 28 percent and any custom rate.
To add GST, multiply the base amount by the rate and add it to the base. To remove GST from an inclusive price, divide the total by one plus the rate and subtract to find the tax. Rates and rules depend on your country and the product category, and they change, so confirm the current rate with official notifications before invoicing.
How to use it
- Choose whether to add or remove GST.
- Select a rate or enter your own.
- Enter the amount.
- Read the base amount, GST amount and total.
Tips and good to know
- In India intra-state sales split GST equally into CGST and SGST.
- Keep invoice rounding consistent with your accounting policy.
- Check exemptions and special rates for your product.
Frequently asked questions
How do I find the amount before GST?
Choose Remove GST and enter the total.
Does it split CGST and SGST?
Halve the GST amount if both apply.
Is this tax advice?
No; verify with a professional.