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GST Tools Directory

Choose a GST calculator for the amount, direction, or compliance task you need.

GST Calculators

GST tools for everyday price and invoice calculations.

GST Calculator

Add GST to a base price or remove GST from a GST-inclusive total.

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Reverse GST Calculator

Calculate backwards from any total price.

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GST Filing, Credit & Rebate Tools

Calculate GST credits, delayed-payment interest, filing late fees, and housing rebates.

ITC Calculator

Calculate Input Tax Credit and Net GST Payable.

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GST Interest Calculator

Estimate interest on delayed GST payments (Section 50).

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GST Late Fee Calculator

Compute GSTR-3B/1/9 penalties and capping.

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New Housing Rebate Calculator

Estimate Canada's federal and provincial GST/HST new housing rebates.

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Country GST Calculators

Use the GST rates and calculation rules for a specific country.

Canada GST/HST Calculator

Add, remove or reverse GST, HST, PST and QST for all 13 Canadian provinces.

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Quebec GST/QST Calculator

Reverse or add Quebec GST 5% + QST 9.975% with parallel calculation.

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Singapore GST Calculator

Add or remove Singapore's 9% GST, with the 10% service charge stack for restaurant bills.

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NZ GST Calculator

Add or remove New Zealand's 15% GST using Inland Revenue's ×3÷23 method.

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Australian GST Calculator

Add or remove Australia's 10% GST with the official ÷11 method for GST-inclusive totals.

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GST Tools Directory FAQ

Q1.What is this tools directory?

This page lists our GST calculators in one place: the general calculator with add and remove modes, the reverse calculator, and the ITC, interest and late fee tools. Use it to find the right tool for your task.

Q2.Which calculator should I use for a quick total?

For a quick calculation, use the GST Calculator on the home page. Choose Add GST for a base price or Remove GST for a total that already includes GST.

Q3.I have a total price including tax and need the breakdown. Which tool?

Use Remove GST on the home-page calculator for a quick breakdown. Use the Reverse GST Calculator when you need the backwards formula, explanation and downloadable calculation.

Q4.Where do I calculate late fees or interest?

Use the GST Late Fee Calculator for GSTR-3B, GSTR-1, and GSTR-9 penalties and capping. Use the GST Interest Calculator for Section 50 interest on delayed tax payment.

Q5.Are these tools free and private?

Yes. All tools run in your browser. No sign-up or server storage of your figures; calculations and history stay on your device.

Disclaimer: This tool provides arithmetic for one GST rate at a time, not tax, legal or filing advice. Check the original transaction's rate, rounding, exemptions, invoice requirements and filing rules before using a result for an invoice or return.