Calculate sale prices, percentage off & savings
The fundamental discount formula is simple: Discount Amount = Original Price × (Percentage ÷ 100). Then subtract from the original price to get your final sale price.
When calculating discounts with sales tax, always apply the discount first, then add tax to the reduced price. This gives you the correct total: Total = (Price × (1 - Discount%)) × (1 + Tax%).
Stacking discounts doesn't add them together! A 20% off + 10% off coupon gives you 28% total savings, not 30%. Each discount applies to the already-reduced price.
The discount formula is: Discount Amount = Original Price × (Discount % ÷ 100). To find the final price: Final Price = Original Price - Discount Amount or simply Final Price = Original Price × (1 - Discount%/100).
To calculate 20% off: Multiply the price by 0.20 (or divide by 5) to get the discount, then subtract from original. Example: $50 × 0.20 = $10 discount. Final price = $50 - $10 = $40. Or simply: $50 × 0.80 = $40.
Use the reverse formula: Original Price = Sale Price ÷ (1 - Discount%/100). Example: Sale price $80 with 20% off → Original = $80 ÷ 0.80 = $100. Use our "Find Original" tab for instant calculation.
Double discounts apply sequentially, not additively. Two 20% discounts don't equal 40% off! Instead: $100 × 0.80 = $80, then $80 × 0.80 = $64. Total discount is 36%, not 40%. Use our "Double" tab to calculate stacking discounts.
First apply the discount to get the subtotal, then add tax: Subtotal = Price × (1 - Discount%), then Total = Subtotal × (1 + Tax%). Our "With Tax" tab does this automatically for any tax rate.
To find what percentage a discount is: Discount % = (Discount Amount ÷ Original Price) × 100. Example: $15 off a $60 item = (15÷60)×100 = 25% off.
Quick mental math: 10% = divide by 10. 15% = 10% + half of 10%. 25% = divide by 4. 30% = 3 × 10%. 50% = divide by 2. Or just use the quick buttons above!
No! All calculations happen directly in your browser using JavaScript. We don't collect, store, or transmit any of your pricing data. Your information stays completely private on your device.
A discount is calculated by multiplying the original price by the discount percentage (expressed as a decimal). For example, to calculate 25% off $80: $80 × 0.25 = $20 discount. The sale price is $80 - $20 = $60.
To find the original price from a discounted price, use our "Find Original" tab. The formula is: Original Price = Sale Price ÷ (1 - Discount%/100). For example, if something costs $75 after 25% off, original = $75 ÷ 0.75 = $100.
To find how much discount you received: Discount % = ((Original Price - Sale Price) ÷ Original Price) × 100. Example: Bought for $60, original was $80 → ((80-60)÷80)×100 = 25% discount.