GST Calculator
Add GST to a net price or remove GST from a gross price at 5%, 12%, 18%, 28% or any custom rate. Built for India and Australia.
GST breakdown
EU VAT? VAT calculator · US sales tax: Sales tax calculator · invoice: Invoice generator.
How GST is calculated
To add GST: GST = net × rate ÷ 100, and gross = net + GST. To remove GST from a gross price: net = gross ÷ (1 + rate ÷ 100), and GST = gross − net. In India, intra-state GST is split 50/50 between CGST and SGST; inter-state uses IGST at the full rate. India's current slabs under GST 2.0 (56th GST Council, effective 22 September 2025) are 0%, 5%, 18% and 40%, with 3% for gold and 0.25% for rough diamonds.
This GST calculator adds or removes Goods and Services Tax with the standard formulas: adding, GST = net × rate ÷ 100 and gross = net + GST; removing (reverse calculation from a tax-inclusive price), net = gross ÷ (1 + rate ÷ 100). For India it also splits intra-state tax into equal CGST + SGST halves and shows IGST for inter-state supplies, matching how invoices must present the components.
India's slabs changed on 22 September 2025 (GST 2.0, 56th GST Council): the 12% and 28% slabs were abolished, leaving 0%, a 5% merit rate, an 18% standard rate and a 40% rate for luxury/sin goods (gold stays at 3%, rough diamonds 0.25%). The old rates remain in the quick buttons marked "(old)" for checking pre-reform invoices. Australia uses 10%, New Zealand 15%, Singapore 9%. This is an estimate for information only, not professional advice. Rate classification for a specific product should be confirmed against official CBIC notifications. Last verified: July 2026.
FAQ
How do I extract GST from a price that already includes it?
Choose "Remove GST". For ₹1,180 at 18%: net = 1180 ÷ 1.18 = ₹1,000 and GST = ₹180. A common mistake is computing 18% of the gross (₹212.40) — that over-states the tax.
When do CGST/SGST apply versus IGST?
Supplies within one state split the rate 50/50 into CGST (centre) and SGST (state): 18% = 9% + 9%. Supplies between states, and imports, charge the full rate as IGST. The invoice must show the split, which this tool mirrors.
What exactly changed in GST 2.0 (September 2025)?
The 56th GST Council collapsed 5/12/18/28 into two main slabs — 5% and 18% — effective 22 September 2025, moved most old-12% goods to 5% and most old-28% goods to 18%, and introduced 40% for sin/luxury goods (tobacco, pan masala, aerated drinks, luxury vehicles). Essentials stay at 0%.
Which rate should I charge for my product?
That depends on official classification, not on a calculator: check the CBIC rate notifications or consult a GST practitioner. This tool guarantees the arithmetic, not the classification.