GST Calculator
Calculate GST amount and total price inclusive of Goods and Services Tax, or extract the GST component from a GST-inclusive price.
How to use this tool
- Enter original price (gst exclusive) and gst rate in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your total price (gst inclusive) and the full breakdown beneath it.
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
Adding GST: GST Amount = Price × (GST Rate / 100) Total = Price + GST Amount
Extracting GST from inclusive price: GST = Inclusive Price × Rate / (100 + Rate)
How it works
GST (Goods and Services Tax) is a consumption tax levied on the supply of goods and services. To add GST, multiply the net price by the GST rate and add to the original price. To extract GST from a GST-inclusive price, divide the inclusive price by (1 + rate) to get the net price, then subtract; equivalently, multiply the inclusive price by rate/(100 + rate). Common GST rates include 10% in Australia, 15% in New Zealand, and 5%, 12%, 18%, or 28% in India.
Worked example
Adding 10% GST to a $1,000 Price
- Original price (exclusive of GST) = $1,000
- GST rate = 10%
- GST amount = $1,000 × 10% = $100.00
- Total price (inclusive of GST) = $1,000 + $100 = $1,100.00
- To extract GST if $1,000 were the inclusive price: $1,000 × 10/110 = $90.91
GST amount = $100.00; Total inclusive price = $1,100.00
Common mistakes to avoid
- Using the wrong formula when extracting GST from an inclusive price: dividing the total by the GST rate gives the wrong answer; the correct formula is GST = Inclusive Price x Rate / (100 + Rate).
- Applying GST to exempt or zero-rated items (fresh food, medical services, education in many GST regimes) and overcharging customers.
- Forgetting that GST collected is a liability to the government, not revenue: businesses remit GST collected minus GST paid on inputs (input tax credits), and treating gross GST inflows as revenue distorts financial records.
Key terms
- What is GST?
- Goods and Services Tax (GST) is a broad-based consumption tax levied on the value added at each stage of production and distribution, ultimately borne by the end consumer.
- What is the difference between GST-exclusive and GST-inclusive prices?
- A GST-exclusive price does not include tax; GST is added on top. A GST-inclusive price already contains the tax component within the stated amount.
- How do you extract GST from an inclusive price?
- GST component = Inclusive Price × (GST Rate / (100 + GST Rate)). For a 10% rate: GST = Price × 10/110.
- What are common GST rates?
- Australia: 10%; New Zealand: 15%; Canada: 5% federal GST; India: 5%, 12%, 18%, or 28% depending on the goods/service category.
- What is input tax credit?
- Businesses registered for GST can claim a credit for GST paid on business purchases (input tax), offsetting it against GST collected on sales, so only the net GST is remitted to the tax authority.
Frequently asked questions
- What is the difference between zero-rated and GST-exempt supplies?
- Zero-rated supplies are taxable at 0%, meaning the seller charges no GST but can still claim input tax credits on purchases used to make those supplies. Exempt supplies are outside the GST system: no GST is charged and no input tax credits can be claimed, which can create hidden costs for businesses.
- How do I claim GST input tax credits?
- In most GST regimes (Australia, New Zealand, Canada), registered businesses can claim a credit for the GST paid on business inputs against the GST collected on sales. The net amount (GST collected minus ITC) is remitted to the tax authority each period.
- At what revenue threshold must an Australian business register for GST?
- Businesses in Australia must register for GST once their annual turnover reaches or is expected to reach AUD $75,000 (or $150,000 for non-profit bodies). Taxi and rideshare drivers must register regardless of turnover.