What is a GST calculator?

A GST calculator splits tax on an amount into CGST, SGST, or IGST. For intra-state sales in India, GST is divided equally into CGST and SGST. For inter-state sales, the full rate applies as IGST.

How do I calculate GST on a GST-inclusive amount?

Taxable value = inclusive amount ÷ (1 + rate/100). GST = inclusive amount − taxable value. Example: ₹11,800 inclusive at 18% → taxable ₹10,000, GST ₹1,800.

Is this GST calculator free?

Yes. The Simple Bills GST calculator is free, works in your browser, and needs no sign-up. For automatic GST on every invoice, see Simple Bills easy GST billing software.

What GST rates does this calculator support?

Common India GST slabs: 0%, 5%, 12%, 18%, and 28%. You can also enter a custom rate for special cases.

Free easy GST tool

GST Calculator India

Easy GST calculator for Indian businesses — split CGST + SGST on same-state sales or IGST on inter-state. Works with GST-inclusive MRP and GST-exclusive taxable amounts. Same paise-accurate rounding as Simple Bills GST invoicing.

Use this free GST calculator to check CGST, SGST, or IGST before you bill — or to verify vendor quotes and MRP. Pick your GST rate, enter the amount, and see the full breakdown instantly.

Enter amount

Taxable value or GST-inclusive total — based on your selection below.

Amount is

GST exclusive GST inclusive

Supply type

Intra-state CGST + SGST Inter-state IGST

GST rate

Custom

GST breakdown

18% GST

Enter an amount to see CGST, SGST, or IGST split instantly.

Taxable value: —
CGST: —
SGST: —
IGST: —
Total GST: —
Grand total: —

Tip: For GST-inclusive prices, taxable value = amount ÷ (1 + rate/100). Simple Bills does this automatically on every invoice line — no manual math at billing time.

How this easy GST calculator works

Whether you sell within your state or ship across India, GST splits differently. This calculator matches how easy GST billing software applies tax on real invoices.

Intra-state vs inter-state

Same state → CGST and SGST (half the rate each). Different states → full rate as IGST.

Inclusive vs exclusive

MRP and vendor quotes are often GST-inclusive. Enter that total and we back out the taxable value correctly.

Paise-accurate rounding

CGST/SGST split reconciles to the exact line total — same rules as Simple Bills and your CA expects.

FAQ

GST calculator — common questions

What is a GST calculator?: A GST calculator works out how much CGST, SGST, or IGST applies on an amount. Intra-state → CGST + SGST (half the rate each). Inter-state → full rate as IGST.
How do I calculate GST on a GST-inclusive price?: Taxable value = amount ÷ (1 + rate/100). Example: ₹11,800 at 18% inclusive → taxable ₹10,000, GST ₹1,800. Select GST inclusive above and enter the MRP.
Is this an easy GST calculator for shop owners?: Yes — pick rate, enter amount, choose intra or inter-state. No Excel, no sign-up. For easy GST on every bill automatically, try Simple Bills GST invoicing.
Which GST rates are supported?: India's common slabs: 0%, 5%, 12%, 18%, and 28%. Use custom rate for other cases. Simple Bills stores rates on your product master so staff never re-enters them.

Tired of manual GST math?

Easy GST billing on every invoice — CGST, SGST, or IGST applied automatically, rolled into your monthly GSTR filing pack.

Try easy GST billing