GST Calculator Guide: Rates by Country, Formulas & Free Tools

Calculate GST for India, Australia, Canada, Singapore, NZ, and more. Compare 2026 rates, learn forward and reverse formulas, and use free country and percentage GST calculators.

GST Calculator Guide

What is GST?

Goods and services tax (GST) is a consumption tax applied to most goods and services. Registered businesses charge GST on sales, claim credits on purchases, and remit the net amount to the revenue authority. The same math applies whether your country calls it GST, VAT, or sales tax — you need the tax-exclusive price, the rate, and the tax-inclusive total.

CGST, SGST, and IGST in India

India splits GST differently from single-rate countries. Use our Indian GST Calculator for intra-state CGST + SGST/UTGST or inter-state IGST on the same invoice. Other countries on this page use one combined tax line at the standard rate.

How to calculate GST

Given a price excluding GST and a rate r%:

When the receipt shows a tax-inclusive total, divide by (1 + rate) to back out the pre-tax price:

Worked example (18% GST)

A ₹1,000 pre-tax invoice at 18% GST adds ₹180 tax for a ₹1,180 total. If you only know ₹1,180, divide by 1.18 to get ₹1,000. Use the Indian GST Calculator to switch between 5%, 12%, 18%, and 28% slabs instantly.

GST rates by country (2026 reference)

Rates change with legislation — always confirm with your tax authority before filing. As of 2026, headline standard rates include:

CountryTax nameStandard rateCalculator
IndiaGST18% (multi-slab)Indian GST Calculator
AustraliaGST10%Australia GST Calculator
SingaporeGST9%Singapore GST Calculator
New ZealandGST15%NZ GST Calculator
CanadaGST / HST5% federalCanada GST Calculator
EgyptVAT14%Egyptian GST Calculator
JerseyGST5%Jersey GST Calculator
JordanGST16%Jordanian GST Calculator
MalaysiaSST10% / 8%Malaysian GST Calculator
MaldivesGST8% / 16% TGSTMaldivian GST Calculator
Papua New GuineaGST10%PNG GST Calculator

Rates are for orientation. Exemptions, zero-rating, and provincial taxes may apply.

When to use a percentage GST calculator

Not sure which country tool fits? Use a fixed-rate calculator when you already know the percentage:

GST vs VAT vs sales tax

VAT and GST are both multi-stage taxes with input credits — the name depends on the country. U.S. sales tax is usually simpler at checkout but varies by ZIP code. Our GST suite covers international GST/VAT math; use the sales tax tool for U.S. receipts.

Who uses a GST calculator?

Shoppers
Compare tax-inclusive shelf prices and spot the true pre-tax cost.
Freelancers & small businesses
Quote invoices with the correct GST split before issuing PDFs.
Students
Practice forward and reverse GST formulas with step-by-step breakdowns.
Expats & travellers
Switch between country calculators (India, Singapore, Australia, etc.) without re-learning the math.

All GST calculators on ShoutingNow

Each tool splits price including GST, GST amount, and price excluding GST with live updates — no submit button required. Pick your jurisdiction or a fixed percentage:

Country GST calculators

Fixed-rate GST calculators ($)

Shopping in the United States? Try our Sales Tax Calculator for state and local rates.

Frequently asked questions

Direct answers to common questions about this topic.

Divide the total by (1 + rate ÷ 100). At 18% GST, divide by 1.18 to get the pre-tax price; subtract to find the GST portion. Every ShoutingNow GST calculator does this live — try the Indian GST Calculator.