Black Friday calculator
List what you plan to buy with the full price and the discount, or the sale price. Add a discount code for the whole basket and delivery. You get the total to pay, how much you save and the real percentage off. Enter the lowest price in the last 30 days to see which “deals” are cheaper than before and which are not.
About the black friday calculator
List what you plan to buy with the full price and the discount, or the sale price. Add a discount code for the whole basket and delivery. You get the total to pay, how much you save and the real percentage off. Enter the lowest price in the last 30 days to see which “deals” are cheaper than before and which are not.
Part of SmartCalcy’s business & shopping tools. It runs in your browser with no account, uses your own currency and units (change them at the top of the page), and gives estimates for information only, so check official guidance before you rely on a result.
How to use the black friday calculator
What it calculates and when to use it
Adds up a Black Friday or Cyber Monday basket: each item’s sale price, an extra discount code, delivery, the total you pay and how much you really save. Enter the lowest price of the last 30 days to check whether each deal is genuine.
How to use it, step by step
- Add each item with its full price and either the percentage off or the sale price.
- Optionally enter the lowest price in the last 30 days.
- Add any discount code for the whole basket and the delivery cost.
- Read your total, your savings and the deal check.
What each input means
- Full price – The normal price before the sale.
- % off or sale price – Enter one; a sale price wins if you enter both.
- Lowest in 30 days – Optional: the cheapest the item has been recently.
- Discount code – An extra percentage off the basket, applied after item discounts.
- Delivery – Added after all discounts.
How to read the results
- You pay – Sale prices less the code, plus delivery.
- You save – Full prices minus what you pay for the goods.
- Is it a deal? – Compares the sale price with the lowest price of the last 30 days.
The formula
Sale price = full price × (1 − % off ÷ 100). Total = sum of sale prices × (1 − code ÷ 100) + delivery. Savings = sum of full prices − sum of sale prices × (1 − code ÷ 100).
A worked example
Headphones £199 at 35% off cost £129.35, but if they were £119 last month, the deal is £10.35 more than the recent low.
Assumptions and limits
- Prices include tax, as shown in shops in most countries outside the US.
- Delivery is not counted as a saving or a discount.
Common mistakes
- Adding percentages: 30% off then 10% off is 37% off, not 40%.
- Trusting a “was” price that the item was rarely sold at.
Frequently asked questions
When is Black Friday?
The day after US Thanksgiving: the fourth Friday in November. Cyber Monday is the Monday after.
Why compare with the lowest price in 30 days?
Some shops raise prices before a sale. In the EU, a price reduction must be shown against the lowest price of the previous 30 days.
Does it work for other sales?
Yes, any sale or shopping list.
Related tools
Your basket
| Item | Full price | Sale price | Off | Is it a deal? |
|---|---|---|---|---|
| Headphones | £199.00 | £129.35 | 35% | ✓ Lowest price |
| Air fryer | £129.00 | £77.40 | 40% | – |
| Winter coat | £90.00 | £67.50 | 25% | ✗ £2.50 more than the lowest |
- Full prices
- £418.00
- Sale prices
- £274.25
- Total to pay
- £274.25
- Total saved
- £143.75