Discount Calculator

Free discount calculator with tax (GST, VAT, sales tax). Calculate percentage off, flat discounts, double/stacked discounts (20% + 10%), and find the original price from a sale price. Compare discount deals across 9 currencies. Essential for shopping sales, coupons, Black Friday deals, and price negotiations.

100
$
Final Price
$75.00
25.0% OFF
$100.00
100 • Price
$25.00
25 • You Save (25.0%)
You Pay 75%
25% Saved
You Save
$25.00
discount applied
Savings
25.0%
of original price
Effective Rate
$0.75
per $1 original

What is a Discount Calculator?

Quickly find savings, final price, and deal comparisons

A discount calculator helps you understand how much money you save when a discount is applied to an original price. It shows the discount amount, final price, and percentage savings, helping you compare offers and make informed shopping decisions.

Online & offline shopping
Sale price comparison
Coupon & promo codes
Budget planning
Find original price
Stacked discounts

Types of Discounts Explained

Percentage vs flat discounts and when each applies

Percentage Discount

Reduces the original price by a fixed percentage. The savings scale with the price.

  • 25% off $100 = $25 saved
  • Better for expensive items
  • Most common in sales

Flat Discount

Subtracts a fixed amount from the price, regardless of the original value.

  • $20 off any item = $20 saved
  • Better for cheaper items
  • Common in coupons

Discount Calculation Formula

Step-by-step formulas for price, discount, and tax

Percentage Discount

Discount Amount = Original Price x (Discount % / 100)
Final Price = Original Price - Discount Amount

Flat Discount

Final Price = Original Price - Flat Discount

With Tax (GST/VAT/Sales Tax)

Final Payable = Discounted Price x (1 + Tax Rate / 100)

How to Calculate Discount Percentage

Find the discount percentage between two prices

To calculate the discount percentage when you know the original price and sale price, use this formula:

Discount % = ((Original Price - Sale Price) / Original Price) x 100

Input

  • Original Price: $80
  • Sale Price: $60

Result

  • Discount = ($80 - $60) / $80 x 100
  • Discount: 25%

To find the original price from a discounted price, divide the sale price by (1 - discount / 100). For example, if an item costs $75 after 25% off: Original = $75 / 0.75 = $100.

Stacked (Double) Discounts Explained

Why 20% + 10% off is not 30% off

Common mistake: Thinking 20% + 10% = 30% off. In reality, the second discount applies to the already-reduced price, giving 28% effective discount.

Final = Price x (1 - D1/100) x (1 - D2/100)
Effective % = (1 - (1 - D1/100) x (1 - D2/100)) x 100

Step by Step

  • Original: $100
  • After 1st (20%): $100 x 0.80 = $80
  • After 2nd (10%): $80 x 0.90 = $72

Result

  • Effective discount: 28%
  • You save $28, not $30
  • Final price: $72

How Discount Works with Tax (GST/VAT/Sales Tax)

Tax is applied after discount to save you more

When both a discount and tax apply, the standard practice is to apply the discount first, then calculate tax on the discounted price. This means you pay tax on a lower amount, resulting in additional savings.

Discounted Price = Original x (1 - Discount%/100)
Final = Discounted Price x (1 + Tax%/100)
🇮🇳

18% GST (India)

  • Price: $100, Discount: 20%
  • After discount: $80
  • GST (18%): $14.40
  • Final: $94.40
🇺🇸

7% Sales Tax (USA)

  • Price: $100, Discount: 20%
  • After discount: $80
  • Sales Tax (7%): $5.60
  • Final: $85.60

Real-Life Examples

Worked examples for percentage, flat, and stacked discounts

Percentage Discount

  • Original Price: $200
  • Discount: 25%
  • Savings: $50
  • Final Price: $150

Flat Discount

  • Original Price: $300
  • Flat Discount: $40
  • Savings: $40
  • Final Price: $260

Stacked Discount

  • Original: $500
  • 1st: 30%, 2nd: 15%
  • Effective: 40.5%
  • Final: $297.50

Find Original Price

  • Sale Price: $75
  • Discount was: 25%
  • $75 / (1 - 0.25) = $75 / 0.75
  • Original: $100

Tips to Maximize Savings

Smart shopping strategies to get the best deals

Compare flat vs percentage

Calculate both to see which saves more. Flat is often better on cheaper items, percentage on expensive ones.

Check tax application order

Discount applied before tax means you pay tax on a lower amount, saving more.

Higher % does not always mean more savings

20% off $50 ($10 saved) is less than 10% off $200 ($20 saved). Compare actual amounts.

Use effective rate to compare deals

The effective price per $1 metric shows the true cost across different discounts and products.

Stacked discounts: order does not matter

20% then 10% gives the same result as 10% then 20%. Both yield 28% effective discount.

Verify the original price

Some retailers inflate original prices before sales. Compare across stores to ensure genuine savings.

Avoid impulse buying

A discount is only a savings if you planned to buy the item. Unplanned purchases at 50% off still cost money.

Frequently Asked Questions

Common questions about discounts, sale prices, and savings

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