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See a '30% off' sale and want to know the actual price you'll pay?

Calculate the final price after any discount — even stacked discounts.

Discount Calculator

Calculate discounts, final prices, and savings with optional tax

Understanding Discount Math

A discount reduces the selling price of an item by a specified percentage or fixed amount. The basic formula is simple: Discount = Original Price x (Discount% / 100). However, real-world shopping often involves stacked discounts, coupons, and tax calculations that make it easy to miscalculate your actual savings.

Stacking Discounts vs. Single Discounts

When multiple discounts are applied sequentially, they compound rather than add. For example, 50% off followed by 20% off means you pay 50% x 80% = 40% of the original price, a 60% total discount — not 70%. This is a common source of confusion during major sales events like Black Friday.

Percentage vs. Fixed Amount Discounts

Percentage discounts scale with the item price, making them more impactful on expensive items. Fixed amount discounts (e.g., $10 off) are more valuable on lower-priced items. To find the best deal, always compare the final price rather than the discount percentage alone.

Common Mistakes

  • ✗Applying multiple discounts sequentially instead of to the original price
  • ✗Confusing percentage off with fixed amount off
  • ✗Forgetting that ‘50% off then 20% off’ is NOT 70% off

Pro Tips

  • ✓Stacking discounts: 50% off then 20% off = 60% total (0.5 × 0.8 = 0.4)
  • ✓Always calculate the final price, not just the discount amount
  • ✓Compare the discounted price per unit when buying in bulk

Real-World Examples

Seasonal sale

A $120 jacket at 30% off saves $36 — you pay $84

Double discounts

40% off then an extra 15% off = 49% total savings

Coupon stacking

$50 item with $10 off coupon + 20% discount = $32 final price

Formula: Discount = Price × (Discount% / 100), Final Price = Price - Discount, Tax = Final × (Tax% / 100), Total = Final + Tax.

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About Discount Calculator

How to Calculate a Discount

Calculating a discount is straightforward. The basic formula is: Discount Amount = Original Price × (Discount Percentage / 100). For example, a 25% discount on a $200 item would be: $200 × 0.25 = $50 discount, resulting in a final price of $150. This calculator handles the math for you instantly—just enter the original price and discount percentage.

When tax is involved, it is typically applied to the discounted price, not the original price. For example, if your discounted price is $150 and the tax rate is 8%, the tax would be $150 × 0.08 = $12, making the total $162. This calculator applies tax to the final discounted price, which is the standard practice in most jurisdictions.

Common Discount Types

Percentage discounts are the most common type, where a fixed percentage is taken off the original price. These are widely used during seasonal sales (Black Friday, Cyber Monday, end-of-season clearances) and are easy to understand. Fixed amount discounts subtract a specific dollar amount from the price, such as “$10 off your next purchase.”

Buy-one-get-one (BOGO) deals effectively offer a 50% discount when you buy two items. Tiered discounts offer increasing savings based on purchase amount (e.g., 10% off $50+, 20% off $100+). Stackable discounts allow multiple discounts to be applied sequentially, though the order matters—a 20% discount followed by a 10% discount is not the same as a 30% discount. This calculator handles single percentage discounts with optional tax.

This utility is provided for informational purposes only. KnowKit is not responsible for any errors in the output.

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Frequently Asked Questions

How do I calculate a percentage discount?

Multiply the original price by the discount percentage divided by 100. For example, a 25% discount on $200: $200 × 0.25 = $50 off, so the final price is $150. This calculator does the math for you instantly.

How do stacked discounts work?

Stacked discounts are applied sequentially, not additively. A 50% discount followed by 20% off means you pay 50% of the price, then 80% of that result: 0.5 × 0.8 = 0.4, so you pay 40% total — a 60% discount, not 70%.

Is tax applied before or after a discount?

In most jurisdictions, sales tax is applied to the discounted price, not the original price. So if an item is $100 with a 20% discount ($80) and 8% tax, you pay $80 + $6.40 tax = $86.40 total. This calculator applies tax to the discounted price.

What is a good discount percentage?

It depends on context. 10-20% is common for seasonal sales, 25-50% for major events like Black Friday, and 50%+ for clearance items. In retail, a 20% discount is considered a standard promotion, while 30%+ is seen as a significant sale.

How do I compare discount deals between stores?

Calculate the final price per unit rather than looking at discount percentages alone. A 30% off a $50 item ($35) is worse than 20% off a $40 item ($32). Also factor in shipping, taxes, and any minimum purchase requirements.

Can discounts be combined with coupons?

Many stores allow stacking percentage discounts with fixed-amount coupons. For example, 20% off plus a $10 coupon on a $100 item: first apply the percentage ($80), then subtract the coupon ($70). Always check the store's coupon policy for stacking rules.