GST Calculator

Last verified: September 2026 against the GST 2.0 slab structure. See how this site is maintained.

Calculate GST (Goods and Services Tax) on any amount. Add GST to a base price or remove GST to find the pre-tax amount.

Net Amount (Including GST)

GST Explained

GST (Goods and Services Tax) is a value-added tax levied on most goods and services. The tax rate varies by product category. Under the GST 2.0 reform (effective September 2025), GST slab rates are 0%, 5%, 18%, and 40%, with legacy special rates of 3% (gold/silver) and 0.25% (rough precious stones) continuing to apply.

Add GST: Total = Amount × (1 + Rate/100)
Remove GST: Base = Amount / (1 + Rate/100)

Current GST slabs in India (GST 2.0, effective September 2025)

SlabApplies to
0% (Nil-rated)Notebooks, pencils, maps, and other specified essential items
5%Essential goods — toothpaste, soap, shampoo, dairy products, medical diagnostic kits
18%Standard rate — most commercial goods and services, electronics, automobiles
40%Luxury and sin goods — aerated beverages, tobacco products, high-capacity motorcycles

The earlier 12% and 28% slabs were removed under the GST 2.0 reform. If calculating GST for a specific product, confirm its current HSN classification — some items moved slabs in the transition.

Worked example: GST on an ₹18,000 invoice at each slab

GST RateGST AmountTotal Invoice Value
5%₹900₹18,900
18%₹3,240₹21,240
40%₹7,200₹25,200

Common GST mistakes

  • Confusing CGST+SGST with IGST. Intra-state sales split the rate into CGST + SGST (e.g. 9%+9% for an 18% item); inter-state sales charge the full rate as IGST. The total tax is the same either way — only the split differs.
  • Applying the wrong slab after the 2025 reform. Several items shifted slabs — always verify current HSN classification rather than assuming last year’s rate still applies.
  • Freelancers/small businesses miscalculating GST on top of already-inclusive quoted prices. Confirm with your client upfront whether a quoted price is GST-inclusive or exclusive before invoicing.

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