How the discount calculator works
Last updated 10 November 2026
Discounts are easy to misjudge. This calculator does the maths either way.
How it works
- Saved = price × discount.
- Price after = price − saved.
- Discount = (original − sale) ÷ original.
Worked example
With the starting figures:
- A discount of 25% on R 799.00 saves R 199.75.
- You pay R 599.25.
Two questions, one tool
Shops show discounts as a percentage or as a new price. This calculator works both ways. Give it the original price and the percentage off, and it shows what you save and what you pay. Give it the original price and the sale price, and it shows the percentage discount.
Stacked discounts
Two discounts in a row are not added together. The second discount applies to the price after the first. A discount of fifty percent followed by another fifty percent is seventy-five percent off in total, not a hundred percent. The calculator lets you apply a second discount to see the real result.
Compare like with like
- Check whether a price includes VAT before you compare it with another price.
- Check delivery costs, which can cancel a discount.
- Compare the price per unit or per kilogram when pack sizes differ.
- Check whether the original price was a real price someone paid, or only a number on a label.
For shops and sellers
If you run a business, a discount comes out of your profit, not only your price. A discount that looks small can wipe out a large share of your margin. Use the markup calculator and the profit margin calculator to check what is left after a discount.
A note on rounding
The tool shows rands and cents. The sums are done with full precision and rounded only for display, so a total may differ from a till slip by a cent where a shop rounds each line.
A shopper's check
Before you buy on sale, work out the price per unit with and without the discount, and check the original price against what other shops charge. A deep discount on an inflated price can still cost more than a small discount somewhere else. The calculator takes the guesswork out of the arithmetic, and the comparing is up to you.
Things to watch
- Two discounts in a row are not added together. Take the second off the new price.
- A discount of 50% followed by another 50% is 75% off in total, not 100%.
- Check whether a sale price already includes VAT before you compare it with another price.
Businesses can compare with the profit margin calculator. Read the full disclaimer.