Discount Calculation Formula
Three types of discount calculations cover every shopping scenario:
Sale Price = Original Price × (1 − Discount% ÷ 100)
Savings = Original Price − Sale Price
Discount % = (Savings ÷ Original Price) × 100
Understanding Sale Psychology
Not all discounts represent equal value — retailers use several pricing tactics worth understanding before you spend:
Inflated original prices (anchor pricing): The "was ₹5,000, now ₹3,000" claim is only meaningful if the item was genuinely sold at ₹5,000. Retailers sometimes inflate reference prices to make discounts appear larger. Check if a comparable item elsewhere costs less than the "sale" price.
Stacked discounts are not additive: 20% off followed by an additional 10% off is 28% off total — not 30%. Each discount applies to the already-reduced price. A ₹1,000 item at 20% off = ₹800. Then 10% off ₹800 = ₹720. Total savings = ₹280 (28%), not ₹300.
Loss leaders: Some deeply discounted items are designed to draw customers into a store where full-priced items are also purchased. The loss leader discount is essentially a marketing expense — recognised only if you buy only that item.
Bundle discounts: "Buy 3 for the price of 2" means a 33.3% discount — but only if you actually need 3. Unnecessary items are not savings, they are spending.
Reverse Discount — Finding the Original Price
If you know the sale price and the discount percentage, you can work backwards to find the original price:
Original Price = Sale Price ÷ (1 − Discount% ÷ 100)
Example: A shirt is on sale for ₹630 after a 30% discount. What was the original price?
Original = 630 ÷ (1 − 0.30) = 630 ÷ 0.70 = ₹900
This reverse calculation is useful when:
- You want to verify an advertised discount is genuine
- You received an invoice with discount already applied and need the base price
- You are working backwards from a target sale price to set an original price
A common mistake: "₹630 + 30% = original price" gives ₹819 — wrong! You must divide, not multiply, because the 30% was taken off the original (unknown) price, not added to the sale price.
Discount in Business and Retail
Businesses use discounts strategically for multiple objectives:
Clearance discounts: Moving old inventory before a new season or product launch. Deep discounts (40-70%) recover cash and free shelf space even if margin is sacrificed.
Volume discounts: Rewarding larger purchases — "10% off orders above ₹10,000". The business benefits from larger order sizes and reduced per-transaction costs.
Loyalty discounts: Rewarding repeat customers builds retention. The cost of a 10% loyalty discount is typically less than the cost of acquiring a new customer.
Early payment discounts: B2B contexts often offer "2/10 net 30" — a 2% discount if paid within 10 days rather than the standard 30. This effectively provides a 36% annualised return on the discount (2% over 20 days = 36% annualised), making it an excellent deal for the paying company.
Seasonal discounts: End-of-season sales align inventory levels with demand cycles while maintaining brand perception better than year-round discounting.