Last updated
Quick Reference
- 10% off: multiply by 0.90
- 20% off: multiply by 0.80
- 25% off: multiply by 0.75
- 30% off: multiply by 0.70
- 50% off: multiply by 0.50 (half price)
- 75% off: multiply by 0.25
Use the Discount Calculator at techconverter.me to calculate final prices, amounts saved, and effective discount percentages for any combination of original price and discount — including sequential discounts and tax calculations.
Examples
Example 1: Basic Percentage Discount
/* 20% off a $50 item */
Original price: $50.00
Discount: 20%
Amount saved: $50.00 × 0.20 = $10.00
Final price: $50.00 - $10.00 = $40.00
/* Formula */
Final price = Original × (1 - discount rate)
Final price = $50.00 × (1 - 0.20) = $50.00 × 0.80 = $40.00
Example 2: Fixed Amount Discount
/* $15 off coupon on a $75 purchase */
Original price: $75.00
Discount: $15.00 (fixed amount)
Final price: $75.00 - $15.00 = $60.00
Effective %: $15.00 / $75.00 × 100 = 20%
/* Same $15 coupon on a $200 purchase */
Final price: $200.00 - $15.00 = $185.00
Effective %: $15.00 / $200.00 × 100 = 7.5%
Example 3: Sequential Discounts (Not Additive)
/* 20% sale + 10% coupon — NOT 30% off */
Original price: $100.00
Step 1: Apply 20% sale
After sale: $100.00 × 0.80 = $80.00
Step 2: Apply 10% coupon to discounted price
After coupon: $80.00 × 0.90 = $72.00
Effective discount: ($100 - $72) / $100 = 28% (not 30%)
Amount saved: $28.00
/* The order matters for fixed + percentage combinations */
/* Percentage first, then fixed: */
$100 × 0.80 = $80 - $10 = $70 (effective 30%)
/* Fixed first, then percentage: */
$100 - $10 = $90 × 0.80 = $72 (effective 28%)