"Flat 30% off" is easy. "30% off plus an extra 10% on the discounted price, with a ₹200 coupon above ₹999, and GST on top" is where cashiers lose money and customers lose trust. This discount and percentage calculator does the arithmetic instantly — single discounts, stacked (double) discounts, flat rupee-off, buy-more-save-more, and reverse calculations that tell you what percentage a markdown really was — so you can price festive offers, check a supplier's scheme, or settle a counter argument in seconds.
The formulas behind every offer
- Percentage off: sale price = MRP × (1 − d). At 30% off ₹1,499, the price is ₹1,049.30.
- Stacked discounts do not add. 30% then 10% is 1 − (0.7 × 0.9) = 37%, not 40%. On ₹1,499 that is ₹944.37, not ₹899.40 — a ₹45 difference on every unit if the cashier adds them.
- Flat rupee off: effective % = amount ÷ MRP. A ₹200 coupon on ₹999 is 20.02%; on ₹2,499 it is 8%.
- Reverse: discount % = (MRP − sale) ÷ MRP. A shirt marked ₹1,299 selling at ₹899 is 30.8% off.
- Markup vs margin: a 25% markup on cost is a 20% margin on selling price. Use the profit margin calculator to keep the two straight.
How to use it
- Pick the mode: single discount, double discount, flat off, or "find the percentage".
- Enter the MRP or list price and the discount figures.
- Toggle GST if your price is exclusive of tax and you want the customer's final payable; pick the slab (most retail goods are 5% or 18% since GST 2.0).
- Read the sale price, the rupee saving and the effective discount percentage — the number to print on the tag.
- Copy the result to a price tag or a WhatsApp offer.
Discounting and GST: what the law says
GST is charged on the transaction value after discount if the discount is shown on the invoice (Section 15(3)(a)). A ₹1,000 item at 20% off with 18% GST is taxed on ₹800, so the customer pays ₹944, not ₹980. Post-sale discounts — a quarter-end rebate to a dealer — reduce GST only if they were agreed before the supply and are linked to invoices via a credit note. Trade schemes like "buy 10 get 1 free" are treated as a discounted composite supply; tax the 11 units at the price of 10.
Retail price tags must still show the MRP under the Legal Metrology (Packaged Commodities) Rules; you may show the offer price beside it, but you cannot sell above MRP.
Planning festive and clearance offers
- Know your floor. Gross margin minus discount minus payment-gateway fee must stay positive; a 40% discount on a 45% margin product leaves 5% before rent. Check the gross margin calculator.
- Threshold offers ("₹200 off above ₹999") lift average basket size more than flat percentages.
- Stacked coupon abuse: if your billing software applies a coupon after a percentage discount, make sure the tag's "effective %" matches what the customer will see.
- Clearance math: a 50% markdown needs double the units sold to earn the same revenue; check the inventory turnover before over-ordering for Diwali. The eight-week plan in Festive season 2026 checklist covers timing.
Related tools
- Price tag generator — print MRP, offer price and discount % on grids of labels.
- Profit margin & break-even — see whether the offer still pays rent.
- GST calculator — inclusive and exclusive pricing.
- Percentage calculator — general percentage change and ratio math.
- Seller pricing workflow — for marketplace listings with commissions.