How do you calculate a discount?
Sale price = Original price × (1 − Discount / 100). Amount saved = Original price × Discount / 100. Example: 25% off $120 saves $30 and leaves $90. A quick shortcut is to multiply by the percentage you actually pay: at 25% off you pay 75%, at 40% off you pay 60%.
How do you find the percent off between two prices?
Discount = (Original price − Sale price) / Original price × 100. If a $75 item drops to $60, the difference is $15 and 15 / 75 = 20% off. Always divide by the original price; dividing by the new price gives 25% and overstates the deal.
How do you find the original price from a sale price?
Original price = Sale price / (1 − Discount / 100). An item at $60 after 20% off originally cost 60 / 0.80 = $75. Adding 20% to the sale price gives $72, which is wrong because the discount was taken from $75. For the same reason, undoing a 20% discount takes a 25% price rise.
How do stacked discounts work? Why 20% + 10% is not 30%
The second discount applies to what is left after the first, so rates multiply: Total discount = 1 − (1 − First) × (1 − Second). On $100, 20% off gives $80 and a further 10% gives $72, which is 28% off in total. The order does not matter for percentages, though it can for fixed-amount coupons.
What percent off is buy 3 pay 2?
The effective discount in a buy-X-pay-Y deal is 1 − Y / X. Buy 3 pay 2 is 33.3% off, buy 4 pay 3 is 25%, and 'second item half price' equals 25% across two items. The catch is that you only get that rate if you actually need the extra units.
For sellers: how does a discount affect profit?
A discount lowers price but not cost, so profit falls much faster than the percentage suggests. A $100 product costing $60 earns $40 per unit. At 20% off, the price is $80 and profit halves to $20, so you need twice the sales to earn the same total. Required sales uplift = Profit before / Profit after − 1. At a 30% margin, 10% off needs 50% more sales and 20% off needs 200%. At 40%, the figures for 10%, 20% and 30% off are 33%, 100% and 300%. At 50% they are 25%, 67% and 150%.
What is the deepest discount you can afford?
Without fees, the break-even discount equals your margin. Marketplace commission is charged on the discounted price, so the full formula is: Break-even discount = 1 − Unit cost / (Original price × (1 − Commission rate)). A $100 product with $50 cost and 20% commission breaks even at 1 − 50 / 80 = 37.5%. That is before advertising. Break-even ROAS rises as well: in the earlier example it moves from 100 / 40 = 2.5 to 80 / 20 = 4.0 at 20% off.