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GST (Goods & Services Tax) is a consumption tax used in India, Australia, Canada, New Zealand, Singapore, and several other countries. This calculator adds GST to a net amount or removes it from a gross (tax-inclusive) amount, at whatever rate applies to you.
How it works
Choose whether you're entering a net amount (to add GST) or a gross amount (to remove GST), enter the amount and the GST rate (%), and the calculator applies the corresponding formula — either net × (1 + rate) for adding, or gross ÷ (1 + rate) for removing.
- Enter what are you entering?.
- Enter amount.
- Enter gST rate (%).
- Click Calculate to see your results.
Examples
Adding GST at the common Indian standard rate
A $1,000 net amount at 18% GST comes to a $1,180 gross total, of which $180 is GST.
Who should use it
- Invoicing and pricing calculations for GST-registered businesses.
- Checking a receipt or invoice's GST breakdown.
Industry applications
- Retail, e-commerce, and small business accounting
- Invoicing and bookkeeping
Advantages
- Works both directions — add GST or extract it from a tax-inclusive total.
- Flexible rate input for any country's applicable GST rate.
Limitations
- Doesn't know your specific country/category's actual rate — you need to supply the correct one yourself.
Common mistakes to avoid
- Using the wrong GST rate for your country or product category — always confirm the applicable rate rather than assuming the default.
- Applying the "add" formula to an amount that already includes GST (or vice versa), which double-counts or misses the tax entirely.
Best practices
- Confirm whether the figure you're starting from already includes GST before choosing add vs. remove.
- Keep a note of which GST rate applied to a given calculation, since rates can vary by product/service category even within one country.
Tips
- If you only know a gross, tax-inclusive total, use "remove GST" rather than trying to reverse-engineer the net amount by hand.