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Free Online GST Calculator

Enter an amount and GST rate to add tax to an exclusive price or remove tax from an inclusive bill. Presets cover common India GST slabs (5%, 12%, 18%, 28%) plus a custom percent.

Enter the price before GST (exclusive amount).

18

Result

Base (exclusive)₹1,000.00
GST (18%)₹180.00
Total (inclusive)₹1,180.00

Percentage calculator · Discount calculator

How GST inclusive and exclusive prices work

GST (Goods and Services Tax) is added on top of an exclusive (pre-tax) price, or already included in an inclusive price on a receipt.

Add GST: GST amount = Base × (Rate ÷ 100). Inclusive total = Base + GST amount.

Remove GST: Base = Inclusive ÷ (1 + Rate ÷ 100). GST amount = Inclusive − Base.

Example: ₹1,000 + 18% GST → ₹180 tax → ₹1,180 inclusive. ₹1,180 inclusive at 18% → ₹1,000 base + ₹180 GST.

For general percent math, use the percentage calculator. For invoice discounts before tax, try the discount calculator.

Worked examples

Real problems you might enter in the calculator above, with short walkthroughs.

  • Add 18% GST to ₹1,000 (exclusive)

    1,000 × 0.18 = 180. Inclusive = 1,180.

    AmountBase ₹1000 · 18% GSTGST splitGST ₹180 · Total ₹1,180

  • Remove 18% GST from ₹1,180 (inclusive)

    1,180 ÷ 1.18 = 1,000 base. GST portion = 180.

    AmountInclusive ₹1180 · 18% GSTGST splitBase ₹1,000 · GST ₹180

  • 5% GST on ₹2,500 restaurant bill (exclusive)

    Lower slab example for essentials or certain categories.

    AmountBase ₹2500 · 5% GSTGST splitGST ₹125 · Total ₹2,625

  • 12% GST on ₹8,000 invoice

    Mid-rate slab often used on many goods and services.

    AmountBase ₹8000 · 12% GSTGST splitGST ₹960 · Total ₹8,960

Frequently asked questions about the GST calculator

  • How do I add GST to a price?

    Multiply the exclusive amount by the GST rate divided by 100. Add that tax to the base. Example: 18% on ₹1,000 → ₹180 GST → ₹1,180 total.

  • How do I remove GST from an inclusive price?

    Divide the inclusive amount by (1 + rate ÷ 100). Subtract that base from the inclusive total to get the GST portion.

  • Which GST rate should I use?

    Rates depend on the product or service and current law (common slabs include 5%, 12%, 18%, and 28% in India). Confirm with your invoice or accountant.

  • Is CGST and SGST included?

    This tool uses a single combined GST percent. For split CGST/SGST, halve the rate for each half only when your invoice uses equal state and central components.

  • Is this GST calculator free?

    Yes. Calculations run in your browser with no signup.