Discount Calculator
Use this free discount calculator to calculate sale prices, discount amounts, total savings, and effective discount rates. Add multiple items, compare sale prices, apply stacked discounts correctly, find an original price from a sale price, or work out the discount percentage you actually received.
✓ Stacked discounts compound
20% off followed by another 10% off produces a 28% effective discount, not 30%. The calculator compounds each discount against the reduced price.
⚠ Discount before GST
If the price entered is before GST, this tool can apply the discount first and then add GST to the discounted amount using the summary toggle.
ⓘ Bulk shopping list
Add multiple products with their own prices, quantities, and discount rates to compare savings and calculate one combined total.
Your last saved carts
Add an item and it'll be saved here automatically.
CalcuHive — Discount Summary
| Item | Qty | Discount | Final | Saved |
|---|
Find the original price
Enter a sale price and discount percentage to calculate the original price before the discount was applied.
Find the discount percentage
Enter the original price and sale price to calculate the percentage discount and see how much of the original price you saved.
How to calculate a discount
A discount calculator converts a percentage discount into the amount saved and the final sale price. It can also help you compare several products, check stacked discounts, and work backwards from a sale price to an original price.
Calculate the final price
First convert the discount percentage to a decimal, then multiply the original price by 1 minus that rate. For example, 20% off $100 saves $20, leaving a final sale price of $80.
Find how much you save
Subtract the sale price from the original price to find the discount amount. For multiple products, add each line-item saving to get the total amount saved.
Apply discounts one after another
Stacked discounts are applied one after another. For example, 20% off followed by 10% off leaves 72% of the original price, giving an effective discount of 28%.
Four steps to calculate your discount
Enter the item
Enter the product name, original price, and quantity so the calculator can include the item in your cart total.
Enter the discount
Enter the main discount percentage and, if applicable, a second discount that is applied after the first.
Add to cart
Add the item to calculate its final price and savings, then repeat the process for other products in your shopping list.
Review the total
Review the total original price, total amount saved, effective discount, and optional GST-inclusive total.
Stacked discount examples
These examples show two percentage discounts applied one after another to a $100 item. Because the second discount is taken from the reduced price, the percentages are compounded rather than added.
| Discount 1 | Discount 2 | Total effective discount |
|---|---|---|
| 20% | 10% | 28% |
| 30% | 15% | 40.5% |
| 50% | 20% | 60% |
| 25% | 25% | 43.75% |
Discount calculator FAQs
How do stacked discounts actually work?
Stacked discounts are applied one after another to the reduced price rather than added together. For example, 20% off $100 leaves $80, and another 10% off $80 leaves $72. The effective discount is therefore 28%, not 30%.
How do I find the original price from a sale price?
Divide the sale price by 1 minus the discount rate expressed as a decimal. For example, if $80 is the sale price after a 20% discount, divide $80 by 0.80 to find an original price of $100.
How do I work out what discount percentage I got?
Subtract the sale price from the original price, divide the saving by the original price, and multiply by 100. For example, saving $20 on a $100 item means the discount percentage is 20%.
Does the discount apply before or after GST?
If the price you enter is before GST, the discount is applied first and GST is then added to the discounted amount. If a retailer gives you a GST-inclusive price, the way the discount is displayed or calculated can differ, so check the retailer’s final checkout price.
Related reading
How Stacked Discounts Work
See why stacked discounts are compounded and how a second percentage discount changes the final sale price.
Learn how stacked discounts work →How to Spot a Fake Sale
Learn how to compare the original and sale prices and spot misleading or inflated discount claims.
Learn how to spot a fake sale →Discount vs GST: Which Comes First?
Understand how the order of a discount and GST can change the final amount you pay.
Learn about discount vs GST →This calculator provides estimates based on the prices and percentages you enter. Retailer terms, rounding, and promotional conditions can vary — always check the final price at checkout.