Discount calculator
Enter a price and a discount to see the sale price, with a second discount and sales tax if there are any. Two more tools on the page give the percent off between two prices and the original price.
Price after a discount
This answer is for the example values in the boxes above. $80.00 with 25% and then 10% off. Change the boxes to see your own answer.
25% off and then 10% off is 32.5% off, not 35%: the second discount comes off the price that the first one leaves.
What percent off is it?
Find the original price
How it works
The first tool takes the discount off the price, then a second discount off what is left, then adds sales tax to that. The second divides the saving by the original price, which gives the percent off. The third works backward: it divides the sale price by one minus the discount to find the price before it.
Prices count cents, and percents can have up to four decimals, so a tax rate such as 8.875 works. A discount can be anything up to 100 percent.
A worked example
A jacket costs $80 and is 25 percent off, and the till takes another 10 percent off. The first discount leaves $60.00, and 10 percent of that is $6.00, so the jacket costs $54.00. You save $26.00, which is 32.5 percent of $80 and not 35 percent.
With 8 percent sales tax on the $54.00, the tax is $4.32 and you pay $58.32.
How two discounts combine
Take 20 percent off $100 and you have $80. Take 10 percent off that and you have $72, so you saved $28, or 28 percent. Two discounts of 20 percent leave $64, which is 36 percent off.
To find the combined discount, multiply what each one leaves and take that from 1: 0.8 × 0.9 is 0.72, and 1 - 0.72 is 0.28.
Rounding to the cent
A price is rounded once, at the end, and a half cent goes up. $24.50 less 15 percent is exactly $20.825, so the sale price is $20.83 and the saving is $3.67.
What it leaves out
The tax is figured on the price after the discounts. The calculator does not know how a store or a state treats a coupon, and it has no shipping or deals such as buy one, get one. It refuses a price above $1,000,000,000.
Questions
How do I calculate a discount?
Multiply the price by the percent off, written as a decimal, and take that away. 25% off $80 is $20, so you pay $60.
What happens when there are two discounts?
The second comes off the price that the first leaves, so the two do not add up. 20% off and then 10% off a $100 item gives $72, which is 28% off and not 30%.
How do I find the percent off?
Take the sale price from the original price, divide by the original price and multiply by 100. From $80 down to $60 is $20 over $80, which is 25% off.
How do I find the price before a discount?
Divide the sale price by one minus the discount, written as a decimal. $60 after 25% off is $60 divided by 0.75, which is $80.
Is the sales tax figured before or after the discount?
The tax box applies your rate to the price after the discounts. If a receipt works another way, trust the receipt.
Why is a half cent rounded up?
The calculator rounds the sale price once, to the cent, on the exact amount, and a half cent goes up. $24.50 less 15% is exactly $20.825, so the sale price is $20.83.
Published .