Discount Calculator

"Extra 10% off on 30% off" is not 40% off. The second percentage is taken from the already-reduced price, so it is worth less than it looks. Thirty per cent off leaves 70% of the price standing; a further 10% removes 7% of the original, not 10%. The real saving is 37%.

The gap widens as the discounts get bigger, which is exactly when shoppers are least likely to check. Here is every common pairing on a ₹1,000 item:

The 50% + 50% row is the one worth remembering, because it is the case where the intuition fails hardest: it is 75% off, and the item never becomes free. No sequence of percentage discounts, however many you stack, can ever reach zero.

There is one piece of good news in the arithmetic. Two percentage discounts commute — 30% then 10% and 10% then 30% both land on ₹1,259.37 from ₹1,999. So if a store applies your coupon in a different order than you expected, the total does not change. That stops being true the moment a flat amount enters, which is the next section.

Percentages commute with each other; a percentage and a flat amount do not. On a ₹1,999 item with 30% off and a ₹200 coupon:

• 30% first, then ₹200 off → ₹1,399.30 − ₹200 = ₹1,199.30
• ₹200 off first, then 30% → ₹1,799 × 0.70 = ₹1,259.30

Sixty rupees apart, from the same two offers. Taking the percentage first is better for you, because the flat amount then comes off a smaller figure and keeps its full value. If the flat amount goes first, the percentage discount is partly wasted on money you were never going to pay.

The calculator above applies percentages first and shows both figures when they differ, so you can see which arrangement the seller used. Coupon terms usually specify this — look for phrasing like "applicable on the discounted price". When the terms are silent, the checkout page is the arbiter, and it is worth comparing against the number here before you assume the coupon failed.

This is the mistake that produces the biggest error, and it is easy to make with any calculator that offers a discount field and a tax field side by side. Under the Legal Metrology (Packaged Commodities) Rules, the MRP printed on a package is the maximum price inclusive of all taxes. The Ministry of Consumer Affairs states it plainly: GST is included in MRP and is not to be charged over MRP.

So on a ₹1,999 MRP with 25% off, you pay ₹1,499.25. Adding 18% GST on top of that gives ₹1,769.12 — an overstatement of ₹269.87 for tax that was already in the price. A retailer who actually billed you that way would be charging above MRP.

The correct reading is that the tax sits inside the figure. That ₹1,999 MRP is ₹1,694.07 of taxable value plus ₹304.93 of GST at 18%. After a 25% discount the taxable value falls to ₹1,270.55 and the GST to ₹228.70 — totalling ₹1,499.25, exactly the simple 25% off. The tax falls in proportion, which is why the discount is worth its full face value.

The tool now asks whether your price is tax-inclusive and defaults to yes. In that mode it splits the tax out of the total instead of adding to it, so the payable figure does not move. Choose "add tax on top" only for a genuinely pre-tax number: a B2B quote, an ex-works price, or a US listing before sales tax. If you are working the other direction and need the tax split from a total on any slab, the GST calculator handles that with the CGST/SGST breakdown.

It computes the arithmetic of a stated offer. It cannot tell you whether the offer is real. A percentage is only meaningful relative to its reference price, and that reference is set by the seller. A 70% discount from an inflated "was" price can leave you paying more than a 20% discount elsewhere, and the calculator has no way to know.

The only check that settles it is the absolute figure. Compare what you would actually pay across sellers, and ignore the percentages entirely — they are the part of the offer the seller controls. The Discount % mode above is useful here: enter a competitor's listed price against the MRP to see what discount they are really giving.

Also outside its scope: shipping, payment-gateway or convenience fees, exchange-offer valuations, no-cost-EMI interest that is folded into the price, and any bank-card offer that requires a specific card. Those are added at checkout and can reverse the ranking between two sellers. Your inputs stay in your browser and are not sent to ToolMintX.