GST Calculator
Add GST to a base price, or remove GST from a GST-inclusive price (MRP). Instant CGST/SGST breakup for invoicing.
GST formulas
Add GST: GST = Base × Rate ÷ 100 → Total = Base + GST
Remove GST: Base = Total × 100 ÷ (100 + Rate) → GST = Total − Base
For intra-state sales, GST is split equally between the Centre (CGST) and the State (SGST). For inter-state sales, the full amount is charged as IGST. The split doesn't change what the customer pays — only where the tax goes.
Common examples at 18%
- ₹1,000 service + 18% GST = ₹1,180 invoice (₹90 CGST + ₹90 SGST)
- ₹1,180 MRP at 18% = ₹1,000 base + ₹180 GST
- ₹50,000 laptop (18%): base ≈ ₹42,373, GST ≈ ₹7,627
GST FAQs
Who needs to register for GST?
Businesses with turnover above ₹40 lakh for goods (₹20 lakh for services; lower thresholds in special-category states), all inter-state sellers, and e-commerce sellers generally must register. Voluntary registration is allowed for input credit.
What is input tax credit (ITC)?
Registered businesses can subtract GST paid on purchases from GST collected on sales and pay only the difference — this makes GST a tax on value addition only.
Is GST the same in every state?
Yes — rates are uniform across India. Only the CGST/SGST vs IGST composition changes based on whether the sale crosses state lines.