What is GST Calculator?
This GST calculator runs locally in your browser. Enter an amount, pick a rate (presets: India GST 18%, Australia GST 10%, Singapore GST 9%, New Zealand GST 15%, Canada GST/HST 5%, UK VAT 20%, Malaysia SST 8%, Taiwan 5%) or slide a custom 0%-30% rate. Two modes: Add tax (amount is exclusive — see tax and total) and Remove tax (amount is inclusive — split out base and tax). The base, tax and total display in real time and copy with one click. Everything runs locally — nothing is uploaded. Built for invoicing, quoting, and pricing.
▶Use Cases5 scenarios
- ◆Invoice tax calculation
- ◆Tax-inclusive quoting and pricing
- ◆Cross-border price conversion
- ◆Learning GST/VAT math
- ◆Comparing rates across countries
▶How to Use5 steps
- 1Enter the amount in dollars
- 2Pick a country rate or drag the slider for a custom rate
- 3Toggle Add tax or Remove tax mode
- 4Read base, tax, and total
- 5Copy the result in one click
▶Features8 features
- ✓Free
- ✓No signup
- ✓8 country rate presets
- ✓Custom rate 0-30%
- ✓Add/remove tax modes
- ✓Real-time calculation
- ✓One-click copy
- ✓100% local
▶FAQ7 questions
What is a GST calculator?
An online tax calculator. Input: an amount, a rate (preset or custom 0-30%), and a mode (add or remove tax). Output: base, tax, and total. Used for invoicing, quoting, and pricing. Everything runs locally in your browser — no uploads.
Which country rates are built in?
India GST 18%, Australia GST 10%, Singapore GST 9%, New Zealand GST 15%, Canada GST/HST 5%, UK VAT 20%, Malaysia SST 8%, Taiwan 5%.
What is the difference between Add tax and Remove tax?
Add tax: the amount is exclusive — tax = amount × rate, total = amount + tax. Remove tax: the amount is the final price — base = amount ÷ (1 + rate), tax = amount − base.
Can I use a custom rate?
Yes. Drag the slider for any rate from 0% to 30% in 0.5% steps.
Can the rate exceed 30%?
The slider caps at 30%, covering virtually all real rates; pick a preset for typical country values.
Can I copy the result?
Yes. Copy Result writes an amount/tax/total summary to the clipboard.
Is my data uploaded?
No. All calculation happens locally in your browser with no network requests.