Discount Calculator
Find out exactly how much you save and what the final price is after any percentage discount. Enter the original price and the discount, and get the sale price and savings amount instantly.
How It Works
Discount calculations appear everywhere — retail sales, coupon stacking, negotiated pricing, and seasonal promotions. The math is simple, but doing it correctly in your head while shopping or comparing deals takes a moment. This tool does it instantly.
Core formulas:
Discount amount = Original price × (Discount % / 100)
Sale price = Original price − Discount amount
= Original price × (1 − Discount % / 100)
Savings % = (Discount amount / Original price) × 100
Worked example: A jacket costs $149.99 and is 35% off.
Discount amount = 149.99 × 0.35 = $52.50
Sale price = 149.99 − 52.50 = $97.49
Stacking discounts: If a $100 item is discounted 20%, then an extra 10% off, you do not get 30% off. You get:
After first discount: 100 × 0.80 = $80
After second discount: 80 × 0.90 = $72
Total savings: $28, which is 28% — not 30%.
Finding the original price from a discounted price: If you know the sale price and the discount percentage, you can reverse-engineer the original: Original = Sale price / (1 − Discount% / 100). So if a sale price is $60 at 25% off: Original = 60 / 0.75 = $80.
Tax on discounted items: Sales tax is typically applied to the post-discount price. So a $100 item at 25% off with 8% tax: sale price = $75, tax = $75 × 0.08 = $6, total = $81.
Comparing deals: A buy-one-get-one-50%-off deal on two identical $50 items costs $75 (one at $50, one at $25) — effectively 25% off total, not 50%. Always calculate the per-unit or total-basket price when comparing promotions.
Frequently Asked Questions
How do I calculate 20% off a price?
Multiply the price by 0.80 (which is 1 − 0.20). So 20% off $85 = $85 × 0.80 = $68. Alternatively, find 20% (85 × 0.20 = $17) and subtract it: $85 − $17 = $68.
What is the difference between discount and markdown?
Both reduce price, but a discount is typically a temporary promotional reduction (a coupon or sale), while a markdown is a permanent price reduction, often applied to clear old inventory. The math is the same; the business context differs.
How do I find the original price if I only know the sale price and discount?
Original price = Sale price ÷ (1 − discount%/100). Example: sale price $45, discount 10%: original = 45 / 0.90 = $50.
Does a higher discount percentage always mean more savings in dollars?
No — the absolute saving in dollars depends on the original price. A 50% discount on a $10 item saves $5. A 20% discount on a $200 item saves $40. Always look at both the percentage and the dollar amount.
How do coupon stacks work with percentage discounts?
When applying multiple percentage discounts sequentially, each subsequent discount applies to the already-reduced price, not the original. Two 10% discounts give: (1 − 0.10) × (1 − 0.10) = 0.81, so 19% off total, not 20%.