GST Calculator - Online GST Calculator (Add & Remove)

Calculate GST amounts quickly, split into CGST/SGST/IGST, and compute base vs. total prices.

Reviewed for Budget 2025 • Last updated 22 June 2026 • by Sandesh D.

GST Parameters

Amount₹10,000
Calculation Mode
GST Tax Rate
Transaction Type

GST Summary

Base Amount (85%)GST Tax (15%)
Base Amount (Excl. GST)₹10,000
GST Tax Amount (18%)₹1,800
CGST (Central Tax)₹900
SGST (State Tax)₹900
Total Amount (Incl. GST)₹11,800
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Calculation Methodology & Rules

The GST Calculator simplifies tax computation for goods and services in India, supporting both GST addition and removal.

1. Add GST (Exclusive Amount)

If your starting price is exclusive of tax, the GST and total values are:

GST Amount = Net Price × (GST % / 100)
Total Price = Net Price + GST Amount

2. Remove GST (Inclusive Amount)

If the price already includes GST and you want to extract the base price:

Base Price = Inclusive Price / (1 + GST % / 100)
GST Amount = Inclusive Price - Base Price

3. Intra-State vs. Inter-State Rules

  • Intra-State: Tax is split 50-50 into CGST and SGST.
  • Inter-State: The entire tax amount is designated as IGST.
For detailed rules, formulas, references, and official guidelines, see the complete Ganakam Calculation Methodology.

Frequently Asked Questions

To add GST, multiply the net price by the GST rate percentage (e.g. Price × 1.18 for 18% GST). To remove GST from a GST-inclusive price, divide the total price by 1 plus the GST rate decimal (e.g. Inclusive Price / 1.18).

CGST (Central GST) and SGST (State GST) are applicable for intra-state transactions (within the same state) and split the tax equally. IGST (Integrated GST) applies to inter-state trade and is collected entirely by the Central Government before distribution.

Standard GST slabs in India are 5%, 12%, 18%, and 28%. A few essential items are exempted (0%), and luxury/sin goods may attract an additional cess on top of the 28% slab.