How to Remove GST from a Price: Quick Method + Free Calculator

Whether you’re preparing a business report, adjusting invoices, or working out the base price of a product, knowing how to remove GST from prices is a valuable skill for both business owners and individuals in Australia. GST (Goods and Services Tax) is a 10% tax included in most goods and services, but there are times when you need to calculate the original amount before GST was added. 

This guide will walk you through quick methods, including the GST-inclusive to exclusive formula, the divide by 11 method, and free calculator tools, so you can accurately determine GST-exclusive prices every time.

GST Inclusive to Exclusive Formula

The GST inclusive to exclusive formula is the standard way to work out the original price before GST was added. This is useful when you already have the total amount (GST-inclusive) and want to find the base amount (GST-exclusive). In Australia, where GST is set at 10%, the formula is helpful when you need to remove GST from prices accurately.

GST-exclusive price = GST-inclusive price ÷ 1.1

For example, if a product costs $110 including GST, you simply divide $110 by 1.1 to get $100, which is the price before GST. This method is recommended by the Australian Taxation Office (ATO) because it is quick, accurate, and works for both goods and services. You can calculate GST-Inclusion and GST-Exclusion by this ATO’s Certified GST calculator.

Divide by 11 GST Method

The divide by 11 GST method is one of the fastest ways to find the GST portion of a GST-inclusive price in Australia. This approach is based on the “one-eleventh” rule recommended by the ATO. Since GST is 10% of the GST-exclusive price, it makes up exactly one-eleventh of the GST-inclusive price, making it easy to remove GST from prices quickly and accurately.

Formula:
GST amount = GST-inclusive price ÷ 11

For example, if the total cost is $220 including GST, divide $220 by 11 to get $20. This $20 is the GST component, and subtracting it from the total leaves you with the GST-exclusive price of $200. This method is perfect for quick back-calculations without needing a calculator app.

How to Find GST Component Australia

If you need to work out exactly how much GST is included in a price, there are a couple of straightforward methods you can use. The most common way to find the GST component Australia-wide is by applying the one-eleventh rule to GST-inclusive amounts. Simply take the total price (including GST) and divide it by 11 to get the GST portion, which helps you remove GST from prices accurately. Get accurate GST components with this calculator for Australia.

Example:
A GST-inclusive invoice total is $550. Divide $550 by 11, and you’ll find that $50 is the GST component. Subtract this from the total, and you’ll get the original GST-exclusive amount of $500.

For larger invoices or when working with multiple line items, you might prefer to use a GST-inclusive to exclusive formula or a GST calculator for better speed and accuracy.

GST Back-Calculation AU

The GST back-calculation AU method is useful when you have a GST-inclusive total and want to determine both the GST amount and the GST-exclusive price. This is essentially reversing the GST addition process to find the original price.

Step-by-Step Example:

• • GST-inclusive price: $1,100

• • Using the GST-inclusive to exclusive formula: $1,100 ÷ 1.1 = $1,000 (GST-exclusive price)

• • GST component: $1,100 − $1,000 = $100

Alternatively, you can quickly find the GST portion using the divide by 11 GST method: $1,100 ÷ 11 = $100. Both approaches give the same result and make it easy to double-check your calculations.

This back-calculation technique is especially helpful for businesses reconciling invoices, preparing reports, or auditing past transactions in Australia.

Deduct 10% GST from Total – Quick Shortcut

For a fast and approximate method, you can deduct 10% GST from the total amount to get a rough GST-exclusive price. While slightly less precise than dividing by 1.1 or using the divide by 11 method, this shortcut works well for quick estimates when you need to remove GST from the prices quickly. To deduct 10% GST you can use this calculation tool: “GST Calculator Australia“. 

Example:

• • Total GST-inclusive price: $220

• • Deduct 10%: $220 − ($220 × 0.1) = $220 − $22 = $198 (approximate GST-exclusive price)

This method is convenient for day-to-day calculations when speed matters, but for exact GST reporting or invoices, it’s better to use the GST-inclusive to exclusive formula or a remove GST calculator.

Real-World Examples

Practical examples make it easier to understand how to remove GST from prices in everyday situations:

1. Retail Product

• • GST-inclusive price: $110

• • Using the GST-inclusive to exclusive formula: $110 ÷ 1.1 = $100

• • GST component: $10

2. Freelance Service

• • GST-inclusive invoice: $550

• • Divide by 11 method: $550 ÷ 11 = $50 GST

• • GST-exclusive price: $550 − $50 = $500

3. Wholesale Supply

• • GST-inclusive total: $11,000

• • Back-calculation: $11,000 ÷ 1.1 = $10,000 GST-exclusive price

• • GST portion: $1,000

4. Multiple Line Items

Item	Price (GST-inclusive)	GST Portion	GST-Exclusive Price
Consulting Service	$1,100	$100	$1,000
Software Subscription	$220	$20	$200

Quick Reference Formula Table

Why Accurate GST Removal Matters

Accurately removing GST from prices is essential for both compliance and financial clarity. Businesses in Australia are required by the Australian Taxation Office (ATO) to report the correct GST amounts on all taxable sales. Mistakes in calculations can lead to penalties, audits, or errors in your Business Activity Statement (BAS), so it’s important to know how to remove GST from prices correctly.

Key reasons to ensure accuracy:

• • Legal compliance: Correct GST reporting keeps your business aligned with ATO rules.

• • Financial transparency: Clients and customers can see exactly what portion of the price is tax.

• • Smooth accounting: Knowing the GST component helps with budgeting and cash flow management.

• • Professional credibility: Accurate invoices reflect professionalism and attention to detail.

Using proper methods like the GST-inclusive to exclusive formula, the divide by 11 GST method, or a remove GST calculator ensures your business stays compliant while avoiding costly mistakes.

Conclusion

Knowing how to remove GST from prices is an essential skill for every business owner, freelancer, or service provider in Australia. Whether you use the GST-inclusive to exclusive formula, the divide by 11 GST method, or a remove GST calculator, understanding these methods ensures your pricing is accurate, transparent, and compliant with the Australian Taxation Office (ATO). Accurate GST removal not only helps with legal compliance and reporting but also builds trust with clients by clearly showing the GST component on invoices. By mastering these techniques, you can confidently manage both goods and services, streamline accounting processes, and avoid costly errors in your financial records.