What this calculator does
A big "40% off" sign tells you how the sale price compares with the store's own "was" or list price. It does not tell you whether the price is lower than what you could have paid last month or at another store. This calculator compares the sale price with the price you have actually seen the item for, then adds sales tax and shipping so you see the real amount you pay at checkout. It also shows what it would cost you to send the item back.
How the numbers work
- You pay at checkout = sale price × (1 + sales tax rate) + shipping.
- You really save = the same total at the price you have seen before, minus the total at the sale price. If it is negative, the "deal" costs more than the price you saw.
- Discount the store shows = (was price − sale price) ÷ was price.
- Discount vs the price you have seen = (your price − sale price) ÷ your price.
- Per item = the checkout total ÷ the number of items in the pack, useful for multipacks and groceries.
- Cost if you return it = return shipping + restocking fee (a percentage of the sale price).
The sales tax uses your state's rate plus the average local rate published by the Tax Foundation for January 1, 2026. Your exact rate depends on your city and county, and some states tax clothing, food or other items differently, so type your own rate if you know it.
An example
A TV is on sale for $299. The store says it "was" $499, a 40% discount. You saw it for $349 at another store last month. In Texas, the state rate plus the average local rate is 8.20%, so you pay about $323.52 at checkout. At $349 you would have paid about $377.62, so you really save about $54, or 14%, not 40%. If the TV does not fit and the store charges $15 to ship it back, returning it costs $15.
How to know the price you have seen
The best comparison is your own record. In the weeks before a sale, write down the prices of the things you plan to buy, or check the same model at two or three other stores on the day. Compare the exact model number: some products sold on sale days are special models made for the event, so a lower price can mean different parts or features.
Before you buy
- Read the return policy: how many days you have, who pays return shipping, and whether there is a restocking fee.
- Count the extras: tax, shipping, warranties and accessories can turn a deal into an average price.
- Pay with a credit card when you can. Credit cards let you dispute a charge for an item that never arrives or is not as described (FTC).
- Watch for fake stores with prices far below everyone else: see our holiday shopping scams guide.
- Keep it inside your plan: the holiday budget planner tracks what you spend on gifts.
Frequently asked questions
Is a Black Friday price always the lowest price of the year?
No. Some prices are lower at other times, and a big percentage off can be measured from a "was" price the item rarely sold at. Compare with prices you have seen yourself.
Why does the calculator add sales tax?
Because you pay it at checkout in most states. A sale price without tax and shipping makes the deal look better than what leaves your account.
Which sales tax rate is used?
Your state's rate plus the average local rate from the Tax Foundation (January 1, 2026). Your real rate depends on where the item is delivered, so you can type your exact rate.
What is a restocking fee?
A fee some stores charge when you return an item, usually a percentage of the price. Check the store's return policy before you buy.
Is my information saved?
No. The numbers stay in your browser and are not sent to us.