GST Invoice Calculator
Calculate CGST + SGST or IGST for any invoice
₹
Base Amount
—
CGST
—
SGST
—
Total Invoice
—

What is a GST invoice calculator?

A GST invoice calculator breaks down the CGST, SGST, or IGST components for any business transaction. For intra-state supply, GST splits equally into CGST + SGST. For inter-state, IGST applies. This tool also extracts the base price from GST-inclusive amounts.

Formula used

Intra-state: CGST = Base × (rate ÷ 2) ÷ 100 SGST = Base × (rate ÷ 2) ÷ 100 Invoice total = Base + CGST + SGST Inter-state: IGST = Base × rate ÷ 100 Extract base from inclusive price: Base = Total × 100 ÷ (100 + rate)

How to use this calculator

  1. Select Add GST or Extract GST mode
  2. Enter the amount
  3. Select GST rate (5%, 12%, 18%, 28%)
  4. Select supply type (intra/inter-state)
  5. Results shown instantly

Example

Example 1 — IT services invoice, ₹50,000, 18%, intra-state:
CGST (9%) = ₹4,500 | SGST (9%) = ₹4,500 | Total = ₹59,000

Example 2 — Extract base from ₹11,800 (18% inclusive):
Base = 11,800 × 100 ÷ 118 = ₹10,000 | GST = ₹1,800

Example 3 — Restaurant bill ₹2,000 at 5%:
CGST (2.5%) = ₹50 | SGST (2.5%) = ₹50 | Total = ₹2,100

Frequently asked questions

CGST goes to Centre, SGST to State — both for intra-state sales. IGST for inter-state sales goes to Centre which then shares with destination state.
Service charge is optional and voluntary. GST is mandatory. You can refuse to pay service charge; you cannot refuse GST. Service charge is not a government levy.
Small businesses with turnover up to ₹1.5 crore can opt for composition scheme — 1% for traders, 2% for manufacturers, 5% for restaurants. No input tax credit available.