About OnlineGSTCalculator.com

We built this site for a simple reason: every other GST calculator asks for something — a signup, a credit-card funnel after the first calc, an app install — or hides the actual tax split you need on a real invoice.

Here you get plain, instant math that runs entirely in your browser, in a clean light or dark theme that matches your system. There is nothing to register and no data to sell: your amounts never leave your device.

What's inside

✓ GST Calculator (India) — Slab rates, custom rate, CGST/SGST/IGST split.

✓ Reverse GST Calculator — Extract GST from GST-inclusive amounts.

✓ UK VAT Calculator — Net ⇄ gross VAT at 20%, 5% or 0%.

✓ US Sales Tax Calculator — Any state or local combined rate.

✓ UAE VAT Calculator — Flat 5% VAT in dirhams.

✓ Australia GST Calculator — Flat 10% GST in AUD.

✓ New Zealand GST Calculator — Flat 15% GST in NZD.

✓ Singapore GST Calculator — 9% GST in SGD.

✓ Canada GST/HST Calculator — GST 5% and provincial HST rates.

✓ GST Invoice Generator — Client-side invoicing with per-item tax split.

Accuracy you can trust

All money math is computed in integer minor units (paise/cents) with half-up rounding applied only at the last step — the same way tax engines work — so totals reconcile exactly with invoices, e-way bills and GSTR filings.

Disclaimer

Calculators on this site are reference tools, not tax advice. Rates reflect current published schedules (GST 2.0 for India, HMRC, FTA, ATO, IR, IRAS, CRA/state) and can change; always confirm against official portals before filing. This site is not affiliated with any tax authority.