GST Calculator
Add or remove GST instantly across every tax slab, with a clear CGST & SGST breakdown.
Summary
What is GST?
Goods and Services Tax (GST) is a single, comprehensive indirect tax on the supply of goods and services in India. Launched on 1 July 2017, it replaced a tangle of earlier taxes — VAT, Central Excise Duty, Service Tax, Entry Tax and Octroi — with one unified system nationwide.
How is GST calculated?
You only need two inputs: the base amount and the applicable rate. India's standard slabs are 5%, 12%, 18% and 28%. For example, on an item priced at ₹1,000 with 18% GST, the tax is ₹180, taking the final price to ₹1,180.
GST calculation formula
GST = (Base × Rate) ÷ 100 | Total = Base + GST
Base = Total × 100 ÷ (100 + Rate) | GST = Total − Base
How to use this calculator
- Pick Add GST if your amount excludes tax, or Remove GST if it already includes it.
- Type the amount — results update instantly as you go.
- Choose a slab (5 / 12 / 18 / 28%) or enter a custom rate.
- Read the base amount, total GST, the CGST/SGST split, and the final total.
GST inclusive vs exclusive
GST-inclusive means tax is already part of the displayed price — nothing extra is added at billing. GST-exclusive means the price is before tax, and GST is added on top when you bill the customer.
Frequently asked questions
What are the current GST slabs in India? +
The four main slabs are 5%, 12%, 18% and 28%. Essential items may be taxed at 0%, and certain goods carry an extra cess. This tool also accepts any custom rate you enter.
What is the difference between CGST, SGST and IGST? +
For sales within one state, the GST is split equally into CGST (to the Centre) and SGST (to the State). For sales between states, a single IGST is charged instead, equal to the combined rate.
How do I remove GST from a total price? +
Switch to the "Remove GST" tab, enter the GST-inclusive amount and the rate. You'll see the original base price and the GST that was included within it.
Is this GST calculator free? +
Yes — completely free, no sign-up, and every calculation runs instantly in your browser.
Disclaimer: This calculator is provided for informational and estimation purposes only. GST rates and rules are set by the Government of India and may change. For filing, registration or precise tax advice, consult a qualified professional or the official GST portal.