To add GST: multiply the base price by (1 + rate/100); for ₹1,000 at 18% the GST-inclusive price is ₹1,180. To remove GST from an inclusive price, divide by (1 + rate/100): ₹1,180 ÷ 1.18 = ₹1,000 base. For intra-state sales the GST splits equally into CGST and SGST; for inter-state sales the full rate is charged as IGST.
About this calculator
A GST calculator computes the Goods and Services Tax on any transaction. You can add GST to a base price to find the final consumer price, or extract GST from an inclusive price to find the base amount and tax separately.
India's GST has multiple rate slabs in 2026: 0%, 5%, 12%, 18%, and 28%, plus a special 3% rate for gold. For intra-state transactions GST splits equally into CGST (collected by the Centre) and SGST (collected by the State); for inter-state transactions a single IGST charge at the full combined rate is collected by the Centre and shared with the destination state.
Businesses use this calculator to set selling prices, raise invoices, and reconcile Input Tax Credit (ITC) on their purchases. Consumers use it to verify the GST charged on a bill is correct.
Common uses
- Calculate selling price by adding GST to a base price
- Extract GST amount from a GST-inclusive invoice (reverse GST)
- Split 18% GST into 9% CGST + 9% SGST for intra-state sales
- Calculate IGST for an inter-state B2B invoice
- Verify GST charged on any bill, receipt, or PO
- Calculate ITC (Input Tax Credit) on business purchases
Frequently asked questions
How do I add GST to a price?
GST-inclusive price = Base × (1 + Rate/100). For ₹1,000 at 18% GST, inclusive price = ₹1,000 × 1.18 = ₹1,180, of which ₹180 is GST.
How do I remove GST from an inclusive price?
Base price = Inclusive ÷ (1 + Rate/100). For ₹1,180 inclusive at 18% GST, base = ₹1,180 ÷ 1.18 = ₹1,000 and GST = ₹180. The shortcut is GST = Inclusive × Rate / (100 + Rate).
What is the difference between CGST, SGST, and IGST?
For intra-state sales, GST is split equally into CGST (Centre) and SGST (State). For inter-state sales, IGST applies at the full combined rate. For example, 18% GST on an intra-state invoice = 9% CGST + 9% SGST; on an inter-state invoice it is 18% IGST.
What are the GST rates in India for 2026?
GST is levied at 5 main rates: 0% (essentials like fresh produce and food grains), 5% (packaged food, transport, restaurants without ITC), 12% (processed food, mobile phones, hotels under ₹7,500/night), 18% (most services, soaps, electronics), and 28% (luxury and sin goods like cars, tobacco). Gold has a special 3% rate.
Is GST inclusive or exclusive by default?
Under Section 12 of the CGST Act, GST is added on top of the base price unless the invoice or contract clearly states the price is inclusive of GST. Always check whether a quoted price is GST-inclusive before paying or invoicing.
How is GST calculated on services vs goods?
The mechanics are identical for both — GST = Taxable value × Rate. The difference is the rate slab: most services attract 18% GST, while goods can fall in 5%, 12%, 18%, or 28% slabs depending on the HSN code.
Who is required to register for GST?
Businesses with annual turnover above ₹40 lakh (₹20 lakh for services, ₹10 lakh for special-category states) must register for GST. E-commerce sellers and businesses making inter-state supplies must register regardless of turnover.