Free online GST calculator for India
GST Calculator Online India
Use this free online GST calculator to add GST to an amount, remove GST from an inclusive price, and see CGST/SGST or IGST breakup instantly.
Formula
Add GST
Final = Amount + (Amount x Rate / 100)
Remove GST
Taxable = Total / (1 + Rate / 100)
CGST + SGST
Each half = GST amount / 2
Free tool
Enter amount and GST rate
GST rate
Result
Final amount after GST
CGST
₹90.0
SGST
₹90.0
For interstate invoices, the same tax amount is usually shown as IGST instead of CGST and SGST split. Product classification, exemption, and compensation cess can change the applicable rate.
Calculation history
Recent GST checks
Saved locally on this device for quick comparisons.
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Beyond quick GST math
Turn GST calculations into a billing workflow.
Use the signed-in workspace for customer masters, recurring invoices, purchase GST tracking, and report-ready GST summaries.
GST basics
What is GST?
GST is the Goods and Services Tax charged on many goods and services in India. A GST calculator helps you convert between taxable value, tax amount, and final invoice value without manual spreadsheet math.
Add GST
Start with taxable value and calculate the final selling price.
Remove GST
Start with a GST-inclusive amount and extract the taxable value.
Split GST
Show intrastate CGST/SGST or interstate IGST breakup.
Formulas
GST calculation formulas.
GST exclusive formula
GST amount = Taxable value x GST rate / 100
Rs. 1,000 at 18% GST becomes Rs. 1,180.
GST inclusive formula
Taxable value = Inclusive price / (1 + GST rate / 100)
Rs. 1,180 inclusive at 18% gives Rs. 1,000 taxable value.
Reverse GST formula
GST amount = Inclusive price - taxable value
For Rs. 1,180 inclusive at 18%, GST is Rs. 180.
CGST and SGST formula
CGST = GST / 2 and SGST = GST / 2
Rs. 180 GST splits into Rs. 90 CGST and Rs. 90 SGST.
GST rates
Common rate slabs used in India.
GST rates depend on official classification and notifications. This calculator covers the common slabs people need for quick invoice math.
Last reviewed: 29 July 2026
This GST calculator is for quick invoice math. GST rates depend on official HSN/SAC classification, exemptions, notifications, and special rules, so verify the applicable rate before filing or issuing high-value invoices.
Examples
GST examples for Rs. 1,000.
| Taxable value | Rate | GST | Final amount | CGST + SGST |
|---|---|---|---|---|
| Rs. 1,000 | 5% | Rs. 50 | Rs. 1,050 | Rs. 25 + Rs. 25 |
| Rs. 1,000 | 18% | Rs. 180 | Rs. 1,180 | Rs. 90 + Rs. 90 |
| Rs. 1,000 | 40% | Rs. 400 | Rs. 1,400 | Rs. 200 + Rs. 200 |
Rate table
Common India GST rates.
Quick guide
How to calculate GST online.
Enter the amount
Use the taxable value when adding GST, or the invoice total when removing GST.
Choose the GST rate
Pick 5%, 12%, 18%, 28%, 40%, another slab, or use an HSN/SAC suggestion as a starting point.
Select CGST/SGST or IGST
Use CGST and SGST for intrastate estimates, or IGST for interstate estimates.
Copy, print, save, or share
Use the result actions to copy, print, save as PDF, download CSV, or share the calculation link.
Related tools
Continue your GST workflow.
FAQ
GST calculator questions.
How do I add GST to an amount?
Enter the taxable amount, choose the GST rate, and keep the calculator on Add GST. The final amount is taxable value plus GST.
How do I remove GST from a GST-inclusive amount?
Enter the invoice total, choose the GST rate, and switch to Remove GST. The calculator extracts the taxable value and GST amount from the total.
What is the most common GST rate in India?
Many services and goods use 18%, but the correct GST rate depends on HSN/SAC classification, exemptions, notifications, and product category.
Does this calculator handle CGST, SGST, and IGST?
It shows CGST and SGST as equal halves for intrastate invoices. For interstate invoices, the same total tax is usually applied as IGST.
Which GST rates are available in this calculator?
The calculator includes 0.25%, 3%, 5%, 12%, 18%, 28%, 40%, and a custom rate option for quick GST estimates.
Need custom tools