Double Discount Calculator

Formula

Final price = original price × (1 − first discount) × (1 − second discount).

Worked example

With Original price: 100 currency units, First discount: 20 %, Second discount: 15 %, final price is 68.00 currency units.

Inputs and calculation

Apply the first percentage to the original price. Apply the second percentage to that reduced price, not to the original again. Subtract the final price from the starting price to find savings. The displayed relationship is Final price = original price × (1 − first discount) × (1 − second discount). Keep the fields' displayed units attached when reproducing this relationship by hand.

Worked numerical example

For example, enter original price 100 currency units, first discount 20 %, second discount 15 %. Those inputs produce final price of 68 currency units. The same values also give total amount saved 32 currency units; combined effective discount 32 %.

Holding the other example values fixed, change original price from 100 to 110 currency units. The main output becomes 74.8 currency units. This comparison isolates the effect of that one input.

How to read and use the result

The combined effective discount is smaller than the arithmetic sum of the two rates unless one rate is zero. The second markdown acts on a narrower remaining price base. Compare promotions or verify a two-stage markdown at checkout.

Practical context

A 100 item reduced by 20% costs 80 before the second promotion. Another 15% off that 80 removes 12, leaving 68 and an effective 32% discount from the original price. Reversing the two percentage reductions gives the same final mathematical result if both apply to the same base, although retailer coupon rules can differ.

Assumptions and scope

Both reductions apply sequentially to the same item, and each entered number is a percentage from zero to one hundred. Sales tax and shipping are excluded. Replace the example defaults with measured inputs for your situation and account separately for factors outside these fields.

Checks and common mistakes

A 20% discount followed by 15% is not 35% off the original. Check whether a coupon actually stacks with a sale and which discount applies first under the retailer's rules.

Common questions

What should I verify before using the Double Discount Calculator result?

Fixed-amount coupons are different: taking 10 currency units before or after a percentage discount generally changes the final price. Sales tax is commonly calculated on the discounted taxable price, but tax rules vary by location and promotion. This tool stops at the pre-tax item price so a reader can apply the correct local treatment separately rather than burying it inside an assumed rate.