Discount Calculator
Build a cart of items, apply single or stacked discounts, and see your real total savings — plus reverse calculators to find an original price or work out what discount you actually got.
✓ Stacked discounts compound
20% off, then an extra 10% off, is a 28% total discount — not 30%. This calculator gets that right.
⚠ Discount before GST
Discounts are usually applied before GST is calculated, not after — check the toggle in the summary.
ⓘ Bulk shopping list
Add every item in your cart with its own price, quantity, and discount for one accurate grand 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
You know the sale price and the discount % — find what it cost before.
Find the discount percentage
You know the original and sale price — find the % you actually saved.
Four steps to your total
Enter the item
Name, original price, and quantity.
Enter the discount
The main discount, plus an extra stacked one if there is one.
Add to cart
See the final price and savings, and repeat for more items.
Review the total
Total saved, total after discount, and GST if you need it.
Stacked discount examples
Two discounts applied one after another, on a $100 item.
| Discount 1 | Discount 2 | Total effective discount |
|---|---|---|
| 20% | 10% | 28% |
| 30% | 15% | 40.5% |
| 50% | 20% | 60% |
| 25% | 25% | 43.75% |
Common questions
How do stacked discounts actually work?
Stacked discounts are applied one after another to the reduced price, not added together. A 20% discount followed by an extra 10% off works out to a 28% total discount, not 30%, because the second discount applies to the already-reduced price.
How do I find the original price from a sale price?
Divide the sale price by (1 minus the discount as a decimal). For example, an $80 sale price after a 20% discount means the original price was $80 divided by 0.8, which is $100.
How do I work out what discount percentage I got?
Subtract the sale price from the original price, divide that by the original price, then multiply by 100. For example, saving $20 on a $100 item is a 20% discount.
Does the discount apply before or after GST?
Discounts are almost always applied to the pre-GST price first, then GST is calculated on the discounted amount. This calculator follows that order when the GST option is turned on.
Related reading
Why stacked discounts aren't additive
The maths behind why 20% + 10% off isn't 30% off.
Read article →Discount vs GST: what comes first
Why the order of operations changes your final total.
Read article →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.