GST Calculator

About the GST Calculator

Goods and Services Tax (GST) is India's unified indirect tax on the supply of most goods and services, replacing a web of earlier taxes like VAT, service tax and excise. It applies at standard slabs of 5%, 12%, 18% and 28%, depending on the item or service. Whether you are a business raising invoices or a consumer checking a bill, being able to add or remove GST accurately helps you understand exactly what you are paying or charging.

This calculator works both ways. To add GST, it multiplies the base price by the tax rate and adds it, so a Rs 1,000 item at 18% becomes Rs 1,180. To remove GST from a gross amount, it reverses the maths using base = gross x 100 / (100 + rate), extracting the tax already included in the price. It also splits the tax into CGST and SGST for intra-state supplies, each being half of the total GST.

For registered businesses, GST is collected on sales (output tax) and paid on purchases (input tax), with the input tax credit mechanism ensuring tax is effectively charged only on the value added at each stage. This avoids the earlier problem of tax on tax. Correct GST calculation is essential for compliant invoicing and accurate pricing, so use this tool to verify figures before finalising a quote, bill or purchase.

How to use it

• GST applies at slabs of 5%, 12%, 18% and 28% depending on the goods or service.
• Use add mode for a base price and remove mode to extract GST from a gross amount.
• Intra-state supplies split GST equally into CGST and SGST components.
• Registered businesses can offset output GST with input tax credit on their purchases.