How to use the GST + Discount Calculator
- Choose whether your price is before GST or already includes GST.
- Enter the price and the discount %.
- Pick the GST rate and type of supply.
Formula
Taxable value = Price − (Price × Discount ÷ 100)
GST = Taxable value × Rate ÷ 100
Total = Taxable value + GST
Discount first, then GST
Under GST, a discount given before or at the time of supply and recorded on the invoice is deducted from the transaction value. GST is then calculated on the reduced amount, so the customer saves on the tax too.
Note
Discounts given after the sale (for example year-end incentives) follow separate rules and are usually handled through credit notes. Ask your accountant how to treat them.
Worked example
₹20,000 + GST, 10% discount, 18% GST
- Discount = ₹2,000 → taxable value ₹18,000
- GST = 18,000 × 18% = ₹3,240
- Total = ₹21,240 (₹23,600 without discount)
Customer pays ₹21,240 and saves ₹2,360
Frequently asked questions
Is GST charged before or after discount?
After — on the discounted value — when the discount is shown on the invoice at the time of sale.
How do I apply a discount to an MRP that includes GST?
Choose “Including GST”. The discount is applied to the MRP, and the reduced price is split into taxable value and GST.
Sources and review
Last reviewed on by the BizToolsIndia editorial team. Official references:
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