Sequential discounts vs adding discount percentages

Sequential discounts vs adding discount percentages

Formula & method

Final price = original × (1 − d1) × (1 − d2)
Combined discount = 1 − (1 − d1) × (1 − d2), with discounts expressed as fractions.

Identify the base for each discount. If a promotion takes a second percentage off the reduced price, the two reductions apply to different amounts. Multiplying the remaining fractions handles that difference directly. When both discounts are ordinary percentages applied sequentially, their order does not change the unrounded final result.

A fixed-amount voucher, a maximum-discount cap or a tax rule changes the model. A checkout may also round each stage to a currency’s minor unit, creating a small difference from rounding only the final result.

Worked example

A price of 250 reduced by 15% becomes 212.50. Taking another 5% off gives 201.875, or 201.88 when rounded once to two decimals. The combined discount is 19.25%.

What can change the answer

The table assumes two uncapped percentage discounts and no tax or shipping adjustment. Merchant checkout rounding and promotion terms can differ.