GST Calculator
Add GST to a pre-tax amount or extract the embedded GST from a gross total — for price comparison in Australia, Singapore, Canada and more.
Input Data
Results
At a glance:Goods and Services Tax (GST) is a broad consumption tax on most goods and services, mechanically the same as VAT — charged at each stage, with registered businesses crediting input tax, ultimately borne by consumers. Different from a US-style sales tax charged once at retail. Used in Australia (10%), Singapore (9%), Canada (federal 5%, some provinces add PST/HST), NZ (15%), India. Hong Kong has no GST. This calculator offers 'add' (pre-tax × rate → gross) and 'extract' (gross ÷ (1 + rate) → embedded GST) so you see how much tax is in the price and the true goods value.
Formula
Add: GST = pre-tax × rate; gross = pre-tax + GST.
Extract: pre-tax = gross ÷ (1 + rate); GST = gross − pre-tax.
Rate as decimal (e.g. 10% = 0.10).
$$\text{GST} = \text{Net}\times r,\quad \text{Gross} = \text{Net}\times(1+r)$$$$\text{Net} = \dfrac{\text{Gross}}{1+r},\quad \text{GST} = \text{Gross}-\text{Net}$$How to Use
- Enter the amount: pre-tax in add mode, gross in extract mode.
- Enter the local GST rate (e.g. Australia 10%, Singapore 9%).
- Pick the mode: add or extract.
- View GST, pre-tax and gross total.
GST and gross for pre-tax HK$1,000 at various rates
| GST rate | Pre-tax (HK$) | GST (HK$) | Gross (HK$) |
|---|---|---|---|
| 5% | 1,000.00 | 50.00 | 1,050.00 |
| 7% | 1,000.00 | 70.00 | 1,070.00 |
| 10% | 1,000.00 | 100.00 | 1,100.00 |
| 15% | 1,000.00 | 150.00 | 1,150.00 |
Same HK$1,000 pre-tax: Singapore (9%, former 7%), Australia (10%), NZ (15%) differ. Add GST for the true paid price when comparing.
Case Studies
Case 1: Travel spending in Australia
Miss Cheung sees an item priced pre-tax equivalent to HK$1,000, local GST 10%.
Add mode: GST = 1,000 × 10% = HK$100, gross = HK$1,100.
Some Australian labels include GST, some not — confirm before checkout. If eligible for the TRS refund, she may reclaim that HK$100 on departure.
Case 2: Invoice extraction in Singapore
Mr Chan gets a gross invoice HK$1,090, local GST 9%.
Extract mode: pre-tax = 1,090 ÷ 1.09 = HK$1,000.00; embedded GST = HK$90.00.
Splitting verifies the merchant's invoice and helps separate goods and tax for expense claims.
FAQ
Does Hong Kong have GST?
No. Hong Kong discussed a GST in 2006 but shelved it amid opposition and still has no GST or VAT. GST is met mainly in Australia, Singapore, Canada, NZ and India under their tax systems.
GST vs VAT?
Essentially the same — both indirect taxes charged at each stage on the value added, with input credits. Only the name differs: most European countries say VAT; Australia, Singapore, Canada, India say GST. Calculation is identical.
Common GST rates?
Australia 10%, Singapore 9% (from 2024), NZ 15%, Canada federal GST 5% (some provinces add PST or merge into HST). India has multiple GST slabs (0/5/12/18/28%). Check the local tax authority for the current rate.
Is the displayed price GST-inclusive?
Depends on region and retailer. Australia and Singapore retail prices are mostly GST-inclusive; Canada often shows pre-tax prices and adds at checkout. Check the label or ask before comparing — this calculator handles both modes.
Can tourists reclaim GST?
Some places offer tourist refunds, e.g. Australia's Tourist Refund Scheme (TRS), Singapore's eTRS — meeting a minimum spend and processed at designated shops and on departure. The refund is the embedded GST portion (minus a fee); use extract mode to estimate it first.
Related Tools
References
This calculator's content is reviewed by our Licensed Tax Advisory team. Results are for reference only; please refer to the relevant authorities for the official figures.