Discount Calculator
Discount calculator: sale price, amount saved and effective discount in seconds Free, no sign-up, and it runs in your browser.
Dedicated page: /en/discount-calculator
Applied to the already-discounted price, not added to the first discount.
A flat coupon taken off after the percent discounts.
Tax is charged on the discounted price in most US states.
With "get" below. Buy 2 get 1 free is 33.33% off per item.
Stacked discounts multiply, they do not add: 20% then 15% is 32% off, not 35%. 50% then 50% is 75% off, never free.
A discount is a percent off the price you actually pay. If a coupon takes $20 off a $100 item, tip and tax are worked out on the $80 you paid, not the $100 tag. Check the original price was real before you trust a big percent off.
Quick answer
A discount calculator works out the sale price and what you save. Enter the original price and the discount, or stack two discounts, add a flat coupon and sales tax, and it shows the sale price, the amount saved, the real effective discount and the total with tax.
About this Discount Calculator
Discount calculator: sale price, amount saved and effective discount in seconds It is one of the Money and Finance on ToolUstad, and like every tool here it runs entirely in your browser: nothing you type, paste or open is uploaded to a server, and there is no sign-up or usage limit.
What is a discount calculator?
A discount calculator does the arithmetic behind every sale sign: what does this cost now, how much do I save, and what is the real discount? An $80 item at 20% off costs $64, and you save $16. Add a second 15% discount and it costs $54.40, saving $25.60, which is 32% off, not 35%. Add 7.5% sales tax and the total is $58.48.
How stacked discounts really work
Stacked discounts do not add up. Each one applies to the price left after the one before it. 20% then 10% is 28% off, not 30%: $80 becomes $64, then $57.60. 20% then 15% is 32% off: $80 becomes $64, then $54.40. 25% then 25% is 43.75% off. 50% then 50% is 75% off, not free. Shops know this, and the sign that says an extra 20% off sale items is worth less than it looks.
Percent off, amount off and buy-one-get-one
A percent discount scales with the price: 20% off $80 is $16, and 20% off $800 is $160. A $10 coupon on a $40 item is 25% off, but on a $400 item it is 2.5%. Buy-one-get-one deals are a percent in disguise: buy 1 get 1 free is 50% off, buy 2 get 1 free is 33.33% off, and buy 3 get 1 free is 25% off. The calculator converts each one to the effective percent so you can compare them directly. The reverse mode finds the original price from a sale price: a $54.40 sale at 32% off was $80.
Best practices
- Work out the effective discount, not the headline: 20% then 15% is 32% off, and an extra 20% off a sale item is worth less than 20% of the original.
- Compare a flat coupon with a percent: $10 off beats 20% off on anything under $50.
- Check the tax on the discounted price: the tax is charged on what you pay, not on the original price.
- Convert buy-one-get-one to a percent: buy 2 get 1 free is 33.33% off, which you can compare with any percent discount.
Common mistakes to avoid
- Adding stacked discounts together, which overstates the saving: 20% then 15% is 32%, not 35%.
- Forgetting the sales tax, which adds $4.08 to a $54.40 item at 7.5%.
- Thinking buy 1 get 1 free is a better deal than 50% off, when they are the same.
Who is the discount calculator for?
Shoppers comparing sale signs, small business owners pricing a promotion, and anyone checking whether a stacked coupon deal is as good as it looks. It is also useful at the checkout, where the tax and the quantity turn a simple percent into a total that is hard to do in your head.
Learn: how to use the Discount Calculator
- Pick a mode: sale price, percent off, original price, or buy X get Y free.
- Enter the original price and the first discount, and a second discount if it stacks.
- Add a flat amount-off coupon and the sales tax rate if you want the total with tax.
- Read the sale price, what you save, the effective discount and the total with tax.
- Check the table of common discounts and the stacked-discount truth table.
Features
- Four modes: sale price, percent off, original price reverse, buy X get Y free
- Stacked discounts: first and second percent, with the real combined rate
- Flat amount-off coupon on top of the percent discount
- Sales tax on the discounted price, before or after the discount
- Quantity, with a per-item and a total price
- Common discount table from 5% to 75% with sale price and tax
- Stacked-discount truth table: 20% then 10% is 28%, not 30%
- Worked examples for every mode
Worked example
An $80 item at 20% off, then a second 15% off, costs $54.40. You save $25.60, which is 32% off, not 35%, because the second discount applies to the $64 left after the first. With 7.5% sales tax, the total is $58.48. Buy 2 get 1 free on the same $80 item is $53.33 per item, an effective 33.33% off. A 50% discount followed by another 50% is 75% off, not 100%.
Frequently asked questions
How do you calculate a discount?
Multiply the price by one minus the discount percent. $80 at 20% off is $80 times 0.8, which is $64. To find the percent off from a sale price, divide the saving by the original price.
Do stacked discounts add up?
No. Each discount applies to the price left after the one before it. 20% then 15% is not 35% off, it is 32%: $80 becomes $64, then $54.40. 50% then 50% is 75% off, not 100%. The calculator shows the real combined rate.
Is sales tax charged before or after the discount?
After the discount, in almost every state. The tax is charged on the price you actually pay.
How does buy one get one free work out as a percent?
Buy 2 get 1 free means you pay for 2 of every 3 items, so each item costs two thirds of the price, which is 33.33% off. On an $80 item, that is $53.33 per item. Buy 1 get 1 free is 50% off.
How do I find the original price from a sale price?
Divide the sale price by one minus the discount percent. A $54.40 sale price at 32% off means the original was $54.40 divided by 0.68, which is $80. The reverse mode in the calculator does this for you.
What is the difference between a discount and a sale price?
The discount is the amount taken off, and the sale price is what is left. On an $80 item at 20% off, the discount is $16 and the sale price is $64. The percent off is the discount divided by the original price.
Which is better, 20% off or $20 off?
It depends on the price. On a $50 item, $20 off is 40% off, which beats 20%. On a $200 item, $20 off is 10%, which loses to 20%. The crossover is at $100: 20% of $100 is $20, so above $100 the percent wins.
Do discounts apply to the price before or after tax?
Before tax. The discount lowers the price, and the tax is charged on the lower price. That is the rule in almost every US state, and it is why the calculator applies the tax last.
Related tools
More Money and Finance like this one, plus two picks from other categories. Each opens its own dedicated page.