GST/VAT Calculator
Add or remove GST/VAT, find the tax inside a price, handle discounts and quantities, and compare two rates — with exact reverse calculation.
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- Private browser calculation
Total including GST
₹1,180.00
₹1,000.00 + ₹180.00 GST.
- Base amount
- ₹1,000.00
- Taxable amount
- ₹1,000.00
- GST amount
- ₹180.00
- Total
- ₹1,180.00
At 18%, a tax-exclusive amount of ₹1,000.00 produces a total of ₹1,180.00.
These estimates are for general planning only and are not payroll, tax, legal, accounting or financial advice. Actual take-home pay, deductions and tax obligations may differ. Tax treatment may vary by product, location, registration status and transaction type.
Assumptions and conventions
- Add: total = net × (1 + rate). Remove: net = gross ÷ (1 + rate); included GST = gross − net. Two taxes combine on the same base by default, or compound when selected. Amounts round to 2 decimals.
- Rates are your inputs; presets are common values, not a claim of the current rate for your product.
- Registration status, exemptions and product-specific rules are not modelled.
- Values are calculated at full precision and rounded for display; columns may differ from totals by a small rounding amount.
Adding versus removing tax
Adding tax multiplies the net amount by (1 + rate). Removing included tax divides the gross by (1 + rate) — a common mistake is subtracting the rate instead, which gives the wrong net. Discounts can apply before tax (reducing the tax itself) or after (leaving the tax unchanged); the calculator handles both, plus quantities and a second stacked or compound tax.
Formula
Add: total = net × (1 + r); tax = net × r. Remove: net = gross ÷ (1 + r); included tax = gross − net. Two taxes: combined factor 1 + r₁ + r₂ (same base) or (1 + r₁)(1 + r₂) (compound).
Assumptions
- Rates are your inputs; country presets are commonly used values, not a claim of the current rate for your product.
- Registration status, exemptions and product-specific rules are not modelled.
- Amounts round to 2 decimals after calculation.
Content and formulas reviewed on 2026-08-06. See our methodology for how calculations are built and tested.
Worked example
At 18%, a net amount of 1,000 carries 180 of GST for a total of 1,180. In reverse, the GST included in 1,180 at 18% is 180 — dividing by 1.18, not subtracting 18%.
Frequently asked questions
How do I find the tax inside a tax-inclusive price?
Divide by (1 + rate) to get the net, then subtract: the tax in 1,180 at 18% is 1,180 − 1,180/1.18 = 180. Subtracting 18% of 1,180 (212.40) is wrong.
Are GST, VAT and sales tax the same?
GST and VAT are equivalent value-added taxes with different names. US sales tax is a state/local retail tax with different mechanics — this calculator applies whatever rate you enter, and the US view says so explicitly.
Does a discount reduce the tax?
Only when applied before tax, because it reduces the taxable amount. An after-tax discount reduces what the customer pays but not the tax itself.
When would I use two tax rates?
Jurisdictions with layered taxes (for example a national plus a provincial tax). Choose whether the second tax applies to the same base or compounds on the tax-inclusive amount.
These estimates are for general information only and are not financial, tax, legal, or investment advice. Rates, fees, and lending rules vary by lender and country. Actual costs and outcomes may differ from the projections shown.