Discount Calculator — Percent Off, Sale Price & Savings
This discount calculator instantly computes the sale price and savings when a percentage or fixed discount is applied. Enter the original price and discount to see your final cost, total savings, and price per unit after any applicable taxes.
Calculate Your Discount
Enter the original price and discount percentage to see how much you save.
Frequently Asked Questions
How do I calculate a discount percentage?
Divide the discount amount by the original price, then multiply by 100. Formula: Discount % = ((Original Price - Sale Price) / Original Price) × 100. For example, if a $80 item is on sale for $60, the discount is (80-60)/80 × 100 = 25% off.
How do I take 20% off a price?
Multiply the price by 0.20 to find the discount amount, then subtract from the original price. Or multiply directly by 0.80. Example: 20% off $50 = $50 × 0.80 = $40 sale price (you save $10).
How do I find the original price before a discount?
Divide the sale price by (1 minus the discount rate). Formula: Original Price = Sale Price / (1 - Discount%). For example, if you paid $60 after a 25% discount: $60 / (1 - 0.25) = $60 / 0.75 = $80 original price.
Is 20% off then 10% off the same as 30% off?
No! Stacked discounts are multiplicative, not additive. 20% off then 10% off = 1 - (0.80 × 0.90) = 28% total discount, not 30%. The order doesn't matter mathematically — 10% then 20% gives the same 28% result.
Should I apply sales tax before or after the discount?
Sales tax should be applied after the discount. You only pay tax on the actual purchase price. For example, a $100 item at 20% off with 8% tax: $100 × 0.80 = $80, then $80 × 1.08 = $86.40 final price.
What is the difference between percent off and dollar off?
Percent off removes a percentage of the price (scales with the item cost), while dollar off removes a fixed amount. On a $200 item, 15% off saves $30 while $25 off saves $25. For expensive items, percent off often saves more.
How do I calculate a discount in Excel?
For sale price: =OriginalPrice*(1-DiscountPercent/100). For discount amount: =OriginalPrice*DiscountPercent/100. For example, with $50 in A1 and 20% in B1: =A1*(1-B1/100) gives $40.
How do stacked or double discounts work?
Stacked discounts apply sequentially. Each discount is calculated on the already-reduced price, not the original. To calculate: multiply (1 - first discount) × (1 - second discount). Example: 30% + 15% off = (0.70 × 0.85) = 0.595, so a 40.5% effective discount.
What are fake discounts and how do I spot them?
Fake discounts inflate the original price before offering a 'sale'. Warning signs: unusually high original price, permanent 'sale' pricing, no price history. Check price tracking tools, compare across retailers, and be skeptical of discounts over 50% on non-clearance items.
How much is 30% off $100?
30% off $100 = $70. The discount amount is $100 × 0.30 = $30 saved. Quick tip: for 30% off, multiply the price by 0.70 to get the sale price directly.
How to Calculate Discounts and Sale Prices
Discount Formulas
Percent Off (Sale Price):
Discount Amount = Original Price x (Discount % / 100)
Sale Price = Original Price - Discount Amount
Sale Price = Original Price x (1 - Discount % / 100)
Example: 25% off a $80 jacket: $80 x (1 - 0.25) = $80 x 0.75 = $60 sale price. You save $20.
Find Original Price Before Discount:
Original Price = Sale Price / (1 - Discount % / 100)
Example: You paid $60 after a 25% discount: $60 / (1 - 0.25) = $60 / 0.75 = $80 original price.
Stacked (Double) Discounts:
Effective Multiplier = (1 - Discount1 / 100) x (1 - Discount2 / 100)
Final Price = Original Price x Effective Multiplier
Effective Discount % = (1 - Effective Multiplier) x 100
Example: 20% off then 10% off a $100 item: (0.80 x 0.90) = 0.72, so $100 x 0.72 = $72 final price (28% effective discount, not 30%).
Step-by-Step Examples
Example 1: 25% Off an $80 Item
- Original price: $80.00
- Discount rate: 25%
- Discount amount: $80.00 x 0.25 = $20.00
- Sale price: $80.00 - $20.00 = $60.00
You save $20.00 (25% off) — final price $60.00
Example 2: Stacking 20% Then 10% Off a $100 Item
- Original price: $100.00
- First discount (20%): $100.00 x 0.80 = $80.00
- Second discount (10%): $80.00 x 0.90 = $72.00
- Total savings: $100.00 - $72.00 = $28.00
- Effective discount: 28% (not 30%)
Stacked 20% + 10% = 28% effective discount — final price $72.00
Example 3: Finding the Original Price from a Sale Price
- Sale price: $60.00
- Discount was: 25%
- Multiplier: 1 - 0.25 = 0.75
- Original price: $60.00 / 0.75 = $80.00
The item originally cost $80.00 before the 25% discount
Quick Discount Reference Table
Sale prices for common original prices and discount rates:
| Original | 10% | 15% | 20% | 25% | 30% | 40% | 50% |
|---|---|---|---|---|---|---|---|
| $25 | $22.50 | $21.25 | $20.00 | $18.75 | $17.50 | $15.00 | $12.50 |
| $50 | $45.00 | $42.50 | $40.00 | $37.50 | $35.00 | $30.00 | $25.00 |
| $75 | $67.50 | $63.75 | $60.00 | $56.25 | $52.50 | $45.00 | $37.50 |
| $100 | $90.00 | $85.00 | $80.00 | $75.00 | $70.00 | $60.00 | $50.00 |
| $150 | $135.00 | $127.50 | $120.00 | $112.50 | $105.00 | $90.00 | $75.00 |
| $200 | $180.00 | $170.00 | $160.00 | $150.00 | $140.00 | $120.00 | $100.00 |
Smart Shopping Tips
Is a Bigger First Discount Better?
When stacking two discounts, the order does not matter mathematically. 20% off then 10% off gives the exact same result as 10% off then 20% off. The multiplication is commutative: 0.80 x 0.90 = 0.90 x 0.80 = 0.72. What matters is the total effective discount, which is always less than the sum of the individual percentages.
Percent Off vs. Dollar Off: Which Saves More?
It depends on the item price. A $10 off coupon is better than 10% off on items under $100, but worse on items over $100. The breakeven point is: Breakeven Price = Dollar Off / (Percent Off / 100). For example, $15 off vs. 20% off: $15 / 0.20 = $75. Below $75, take the $15 off. Above $75, take the 20% off.
How to Spot Fake Discounts
Retailers sometimes inflate the "original" price to make discounts look larger. Watch for these warning signs:
- The item is always "on sale" and never sold at the listed original price
- The original price is much higher than the same product at competing retailers
- Discounts over 50% on non-clearance or non-seasonal items
- No price history available (use browser extensions like CamelCamelCamel or Honey to track prices)
- Compare prices across at least 2-3 retailers before trusting a "deal"