Tokkucal
GST Calculator
Work out GST exclusive and GST inclusive amounts in seconds. Enter any base amount or total, pick a standard slab (0%, 5%, 18%, 40%) or a custom rate, and see the base amount, GST amount and total price broken down clearly.
About the GST Calculator
How to Use
- Choose Add GST if you have an amount before tax, or Remove GST if you have a final price that already includes GST.
- Enter the amount.
- Pick a common GST rate (0%, 5%, 18%, 40%) or type a custom percentage — for example 3% for gold and jewellery.
- Press Calculate to see the base amount, GST amount and total.
Formula
GST Exclusive (adding GST to a base amount):
GST = Amount × GST% ÷ 100
Total = Amount + GST
GST Inclusive (extracting GST from a total):
Base Amount = Total × 100 ÷ (100 + GST%)
GST = Total − Base Amount
Example
An item costs ₹1,000 before tax, with 18% GST applied:
GST = 1000 × 18 ÷ 100 = ₹180
Total = 1000 + 180 = ₹1,180
Detailed Explanation
Goods and Services Tax (GST) is applied at different rates depending on the category of goods or services in India. Following the GST 2.0 rate reform effective 22 September 2025, the main slabs are 0%, 5%, 18% and 40% (the earlier 12% and 28% slabs were removed — most 12% items moved to 5%, and most 28% items moved to 18%, with a new 40% slab for luxury and sin goods). Gold and jewellery keep a special 3% rate. Businesses issuing invoices typically add GST to a base price (exclusive calculation), while a shopper looking at a price tag that already includes tax often needs the reverse (inclusive calculation) to see the pre-tax price. See our full GST rates guide for what moved where.
Frequently Asked Questions
What is the difference between GST exclusive and GST inclusive?
GST exclusive means the amount you enter does not yet include GST, and the calculator adds it. GST inclusive means your amount already includes GST, and the calculator extracts the base price and GST portion from it.
What GST rate should I use?
The applicable GST rate depends on the goods or service category. Since the GST 2.0 reform (22 September 2025), most goods and services fall under 5% or 18%, with a 40% slab for luxury and sin goods. Check your invoice or the official GST portal if you are unsure.
Did GST rates change recently?
Yes. Effective 22 September 2025, the old 12% and 28% slabs were removed — most 12% items moved to 5%, most 28% items moved to 18%, and a new 40% slab was introduced for items like tobacco, large vehicles and online gaming.
Can I use this for a custom GST percentage?
Yes. Enter any percentage in the GST rate field — for example 3% for gold and jewellery, which keeps its own special rate outside the standard slabs.