Discount Calculator

Worked examples

Standard 20% Sale on $149 Item

A retail jacket tagged at $149 is on sale for 20% off. Result: Final: $119.20 (Save $29.80).

Discount = $149 × 0.20 = $29.80. Final price = $149 - $29.80 = $119.20.

Stacked Coupon & Sales Tax (30% off + 10% coupon + 8.25% tax)

A $100 electronics accessory with 30% store discount, 10% member coupon, and 8.25% local tax. Result: Final: $68.20 (Save $37.00).

After 30% off: $70.00. Extra 10% off $70: $63.00. Tax (8.25% of $63): $5.20. Total = $68.20.

Frequently asked questions

How do you calculate a discount percentage in your head?

Find 10% of the price by moving the decimal point one place to the left. Then double it for 20%, halve it for 5%, or multiply as needed. For example, on $150, 10% is $15, so 20% is $30, making the final price $120.

How do stacked coupons work (e.g. 20% off plus an extra 10% off)?

An extra 10% coupon usually applies to the already discounted price, not the original price. For example, $100 with 20% off is $80. Taking 10% off $80 takes off $8, leaving $72 (an effective 28% total discount, not 30%).

Is sales tax calculated before or after discounts?

In almost all jurisdictions, sales tax is calculated on the discounted purchase price (the amount you actually pay), rather than the original manufacturer sticker price.

What is the exact mathematical formula for discount price?

Discount Price = Original Price × (1 - (Discount % ÷ 100)). For example, 25% off $80 is $80 × (1 - 0.25) = $80 × 0.75 = $60. Total savings is Original Price × (Discount % ÷ 100) = $20.

How do you find the original price if you only have the sale price and discount?

Divide the sale price by (1 - (Discount % ÷ 100)). For example, if an item is on sale for $45 after a 25% discount: $45 ÷ (1 - 0.25) = $45 ÷ 0.75 = $60 original price.