GST Calculator (Add or Remove GST)

Add GST to a net price or extract GST from a gross price — with CGST/SGST split. Works as VAT calculator too

—Net Amount (excl. tax)
—Tax Amount
—Gross Amount (incl. tax)
—CGST + SGST Split

How to Calculate GST — Both Directions

Adding GST is straightforward: Gross = Net × (1 + rate ÷ 100). An 18% GST on ₹10,000 gives ₹1,800 tax and ₹11,800 total. Removing GST (reverse calculation) trips people up: you divide, not subtract — Net = Gross ÷ (1 + rate ÷ 100). From an ₹11,800 invoice at 18%, the net is ₹10,000 and the tax ₹1,800. Subtracting 18% of 11,800 would give the wrong answer. This calculator handles both directions with one click.

The Indian GST slabs — 5%, 12%, 18% and 28% — are available as preset buttons, and the result shows the CGST + SGST split (half each) needed on intra-state invoices. Any custom rate works too, which makes this equally useful as a VAT calculator (UK 20%, UAE 5%, EU rates) or a sales tax calculator for any country.

Who uses reverse GST calculation?

Shopkeepers pricing MRP-inclusive goods, freelancers whose clients pay a fixed gross amount, accountants reconciling invoices, and anyone claiming input tax credit from a total bill. As with all our tools, calculations run entirely in your browser — no figures are uploaded or stored.

Frequently Asked Questions

Divide the gross by (1 + rate ÷ 100). Example: ₹11,800 at 18% → 11,800 ÷ 1.18 = ₹10,000 net, ₹1,800 GST. Never subtract the percentage directly — that gives the wrong answer.
Four main slabs: 5% (essentials), 12% and 18% (most goods and services), 28% (luxury items). The preset buttons above apply each instantly; a custom rate box covers everything else.
For sales within a state, GST splits equally between Central and State: an 18% GST is 9% CGST + 9% SGST. The calculator shows this split automatically for your invoice.
Yes — GST, VAT and sales tax use identical math. Enter your country's rate (e.g. 20% UK VAT, 5% UAE VAT) and choose add or remove.

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