50% + 20% Off Is Not 70%: How to Calculate Stacked Discounts
Extra 20% off a 50% sale price is a 60% total discount, not 70%. Learn the formula for stacked discounts, flat coupons and capped bank offers.
The short answer
Stacked discounts multiply, they do not add. 50% off plus an extra 20% off is a 60% total discount, because the second discount is taken from the already reduced price: ₹2,000 → ₹1,000 → ₹800. The formula is total discount = 1 − (1 − d1) × (1 − d2). You can check any combination by running the Discount Calculator twice, or by entering the original and final prices in its Find % discount mode.
Shops are not doing anything wrong by advertising "50% + 20% off". But reading it as 70% leads to wrong expectations, especially when comparing two offers.
Why the discounts do not simply add up
A percentage discount is always a percentage of a particular price. The first discount is a percentage of the original price. The second is a percentage of the new, lower price, so it is worth less in rupees.
On a ₹2,000 item:
If the discounts added to 70%, the final price would be ₹600. The difference between what people expect and what they pay is ₹200 on this one item.
Combined discount table
| First discount | Second discount | Not this | Real total discount |
|---|---|---|---|
| 20% | 10% | 30% | 28% |
| 30% | 30% | 60% | 51% |
| 40% | 10% | 50% | 46% |
| 50% | 20% | 70% | 60% |
| 60% | 10% | 70% | 64% |
The bigger the first discount, the smaller the second discount is in rupees.
How to calculate stacked discounts with the calculator
Method 1: apply each discount in turn
2000.Method 2: find the overall percentage
Method 2 is also useful in a shop: if a tag shows a crossed-out price and a final price, enter both to see the real percentage, whatever the sign says.
Flat amount plus a percentage: order matters
When one discount is a fixed amount, the order changes the result. Take a ₹2,000 item with a ₹200 coupon and a 10% sale:
| Order | Calculation | Final price |
|---|---|---|
| ₹200 off first, then 10% | (2,000 − 200) × 0.9 | ₹1,620 |
| 10% first, then ₹200 off | 2,000 × 0.9 − 200 | ₹1,600 |
Taking the percentage first and the flat amount second is cheaper for you, by ₹20 here. You usually cannot choose the order, because the checkout applies discounts by its own rules, but knowing the effect explains why the final price can differ from your estimate.
Capped offers: "10% off up to ₹1,500"
Bank card and coupon offers often have a maximum saving. The real percentage then depends on how much you spend:
| Purchase amount | 10% of purchase | Actual saving (cap ₹1,500) | Real discount |
|---|---|---|---|
| ₹8,000 | ₹800 | ₹800 | 10% |
| ₹15,000 | ₹1,500 | ₹1,500 | 10% |
| ₹20,000 | ₹2,000 | ₹1,500 | 7.5% |
Above ₹15,000 the cap applies, so the percentage keeps falling as the price rises. To compare a capped bank offer with a straight sale discount, calculate the rupee saving for your actual basket, then use Find % discount to turn it into a percentage.
Comparing two offers
Suppose one shop offers 60% off and another offers 50% + 10% off the same ₹3,000 jacket.
- 60% off: ₹3,000 × 0.4 = ₹1,200
- 50% then 10%: ₹3,000 × 0.5 × 0.9 = ₹1,350
The single 60% discount is better by ₹150, even though "50% + 10%" may look like the same 60%.
Always compare final prices, not headline percentages. If the two shops start from different original prices, the higher percentage might not be the cheaper deal at all.
Things that change the final price
- Delivery or convenience fees added at checkout.
- Minimum order values for coupons to apply.
- Discounts that exclude some items in your cart, such as sale items being excluded from a coupon.
- Cashback instead of an instant discount. Cashback that arrives later lowers your effective cost only if you actually receive and use it.
For percentage questions beyond discounts, such as adding tax or finding a percentage increase, see the percentage formulas guide. To work out a discount percentage from two prices in more detail, see how to calculate discount percentage.
Summary
- Two percentage discounts combine as 1 − (1 − d1) × (1 − d2).
- 50% + 20% = 60%, 40% + 10% = 46%, 20% + 10% = 28%.
- With a flat coupon, taking the percentage first gives the lower price.
- A capped offer's real percentage falls as you spend more than the cap allows.
- Compare deals by final price, and use the calculator's Find % discount mode to see the true percentage.
Frequently asked questions
What is 50% off plus an extra 20% off?
It is a 60% total discount. The extra 20% applies to the already reduced price, so ₹2,000 becomes ₹1,000 and then ₹800.
What is the formula for two discounts?
Total discount = 1 − (1 − first discount) × (1 − second discount). For 40% and 10%: 1 − 0.6 × 0.9 = 0.46, a 46% total discount.
Does the order of two percentage discounts matter?
No. 20% then 10% gives the same final price as 10% then 20%. The order does matter when one discount is a flat amount, such as ₹200 off.
How do I find the real discount on a capped bank offer?
Work out the actual rupee saving, then divide by the price. 10% off up to ₹1,500 on a ₹20,000 purchase saves ₹1,500, which is 7.5%.
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