Finance
GST Calculator
Convert between net and gross prices without touching a spreadsheet. Pick whether you’re adding GST to a base amount or stripping it out of a tax-inclusive total.
Add GST to a base price or strip it from a tax-inclusive figure in one step.
GST relationships
Gross = Net × (1 + rate) Net = Gross ÷ (1 + rate) GST = Gross − Net
Rate is expressed as a decimal (e.g., 10% = 0.10). The same formulas handle GST or VAT-style taxes where a single percentage applies to the taxable amount.
How to use
- Enter the amount you know (net or gross).
- Provide the GST rate for your region.
- Choose whether to add GST or remove it, then read net, tax, and gross outputs.
Example
Input: Amount = $120 (net), GST rate = 10%, Mode = Add
Output: GST = $12, Gross = $132
FAQ & notes
Does it support multiple GST tiers?
It focuses on a single rate at a time. Run the calculation separately for each tier if your invoice mixes taxable and non-taxable items.
Can I change currencies?
Yes. The math is percentage based, so simply enter figures in your preferred currency and read the results in the same unit.