About the Discount Calculator
Running a price promotion is one of the most common ways to push a book up the charts, but a cheaper price also means a smaller royalty on every copy. This calculator shows both sides: what the reader pays and saves, and what you earn per copy before and during the sale.
Add your royalty percentage (and, for print books, the printing cost per copy) to see the change in royalty and the sales multiplier: how many times your usual sales volume you need during the promotion to earn the same total royalty. If a 40% discount needs 1.67 times your normal sales just to break even, you know what the promotion has to achieve.
For Kindle eBooks the tool also warns you when a sale price drops below the marketplace's lowest price for the higher royalty option, because the royalty rate itself would then change. For exact royalty figures by format and marketplace, check the Kindle Royalty Calculator or the KDP Royalty Calculator.
How It Works
The sale price is the original price reduced by the discount percentage, and the reader saves the difference.
Royalty per copy is your royalty percentage of the price, minus any cost per copy you enter. It is worked out at the original price and again at the sale price.
The sales multiplier divides the royalty before the sale by the royalty during it. It is only shown when both royalties are above zero.
Formula
- Sale price
- Sale price = Price × (1 − Discount ÷ 100)
- Royalty per copy
- Royalty = Royalty % × Price − Cost per copy
- Sales multiplier
- Multiplier = Royalty before ÷ Royalty during sale
Example
A $4.99 Kindle eBook discounted by 40%
- Original price: $4.99. Discount: 40%. Royalty: 70%.
- Sale price: $4.99 × 0.60 = $2.994, shown as $2.99, so readers save $2.00.
- Royalty before: 70% × $4.99 = $3.493, shown as $3.49 per copy.
- Royalty during the sale: 70% × $2.994 = $2.096, shown as $2.10 per copy, a change of −$1.40.
- Sales multiplier: $3.493 ÷ $2.096 = 1.67 (worked out before rounding).
The sale costs you $1.40 per copy, so you need about 1.67 times your usual sales to earn the same royalty.
Important Notes
- eBook delivery costs for the higher royalty option are not deducted. They are usually a few cents per copy.
- The royalty rate you enter is applied at both prices. If the sale price moves your book into a different royalty band, run the numbers again with the new rate.
- Results are rounded to the nearest cent, so a sale price may differ by a cent from the exact percentage.
- Kindle Countdown Deals in KDP Select have their own royalty rules. Check your KDP dashboard before you schedule one.
- Price changes in KDP can take up to 72 hours to go live, so plan promotions with a margin of time.
Frequently Asked Questions
How much should I discount my book for a promotion?
There is no single answer, but deeper discounts usually need much higher sales to pay off. Try a few percentages and compare the sales multipliers. A multiplier under 2 is easier to reach than one over 3.
What does the sales multiplier mean?
It is how many times your normal sales you need during the sale to earn the same total royalty. A multiplier of 1.67 means 167 copies at the sale price earn about what 100 copies earn at full price.
Will my eBook drop to the lower royalty rate on sale?
It can. Each marketplace has a minimum list price for the higher royalty option, and if the sale price falls below it the lower rate applies. The calculator warns you when that happens, and you can rerun it with the lower rate.
Can I use it for paperbacks?
Yes. Enter your print royalty percentage and the printing cost per copy. The printing cost stays the same during a sale, so print royalties fall faster than the price does.
Why is there no sales multiplier for my numbers?
If the royalty during the sale is zero or negative, no amount of extra sales can match your normal royalty, so the multiplier is not shown.
Should I count page reads during a free or discounted promotion?
Kindle Unlimited page reads are paid separately and are not affected by your list price, so they are not part of this calculation. A promotion can still lift page reads by raising your visibility.
Related KDP Tools
- Percentage CalculatorPercent of a number, percentage change and what-percent-of calculations.
- KDP Royalty CalculatorEstimate your royalty and profit from Kindle, paperback and hardcover sales.
- Kindle Royalty CalculatorCompare the 35% and 70% eBook royalty options including delivery costs.
- Book Deadline CalculatorWork out daily word targets or your finish date from your writing pace.
- Word CounterA fast, private word counter with top-word frequency.
- Character CounterCount characters with and without spaces, plus bytes and limits.