how to calculate a discount percentage (with examples)

Discounts seem simple until someone asks you to work backwards. "This was 350 and now it's 245 — what percent off is that?" Or: "There's a 30% off sale on a 890 item — what do I actually pay?" Both questions are just arithmetic, but the formulas run in opposite directions.

forward: price and percentage → final price

The key insight is that "25% off" means you're paying 75% of the original. Multiplying by 0.75 is faster than calculating the discount amount and subtracting it.

reverse: price and final → discount percentage

This is the more useful direction in practice. You're standing in a store, the tag says "was 2,500, now 1,875" and you want to know if it's actually a good deal or just a manufactured "sale" with a small markdown.

stacked discounts: the trap

Stores sometimes offer "additional 20% off sale items." If the item is already 30% off, that's not 50% total — it's 30% off first, then 20% off the already-reduced price.

The order doesn't mathematically matter (30% then 20% = same result as 20% then 30%), but the total is always less than the simple sum. Two 50% discounts don't make it free — you'd pay 25% of the original price.

vat and discounts: which comes first?

In MENA countries with VAT (Saudi Arabia at 15%, UAE at 5%), the discount is applied to the pre-tax price, then VAT is calculated on the discounted amount. So a 1,000 SAR item at 20% off in Saudi Arabia: discount brings it to 800 SAR, then 15% VAT makes it 920 SAR. You don't pay VAT on the full 1,000.