How do I calculate a 20% discount?

To calculate a 20% discount, multiply the original price by 0.20. For example, if an item costs $100, the discount is $100 × 0.20 = $20. The final price is $100 - $20 = $80.

What is 50% plus 20% off?

It is NOT 70% off. First, take 50% off the original price. Then, take 20% off that *new* lower price. For a $100 item: $100 - 50% = $50. Then $50 - 20% = $40. The total discount is actually 60%.

How do I calculate the discount rate if I know the prices?

Subtract the sale price from the original price to get the savings. Then divide the savings by the original price and multiply by 100. Formula: ((Original - Sale) / Original) × 100.

Home / Finance / Discount Calculator

Discount Calculator

Shopping sales? Don't let the "50% off" signs fool you. Use this calculator to see exactly what you'll pay at the register and how much you're actually saving.

Reviewed by David Chen, CFA | Last Updated: November 2025

Original Price ($)

Discount (%)

You Save: $20.00

Final Price: $80.00

How to Calculate Discounts (Without Getting Tricked)

Retailers are masters of psychology. They use bright red signs and "limited time offers" to make you buy things you don't need. But math doesn't lie.

Expert Tip from David Chen, CFA

"The most dangerous number in a store is 'Up to'. When you see 'Up to 70% Off', assume most things are 20% off. Also, remember that a 50% discount on a price that was inflated by 100% yesterday isn't a deal—it's a marketing trick."

The "Double Discount" Trap

You see a sign: "Take an EXTRA 20% off already reduced items!"

If a shirt is 50% off, and you get an extra 20% off, is it 70% off? No.

Common Mistake: Adding Percentages

Percentages don't stack like blocks.

The Math:
$100 Shirt → 50% off = $50.
Take 20% off the $50 = $10 discount.
Final Price = $40.
Total Discount = 60%, not 70%.

Discount Formula

The math is simple:

                    Savings = Original Price × (Discount Percentage / 100)

                    Final Price = Original Price - Savings