Discount & Sale Price Calculator

A 40% discount followed by an extra 10% off does not produce a 50% reduction. The second discount applies to the price that remains after the first one, so a $120 jacket marked down 40% costs $72 before the extra discount — and 10% of $72 is $7.20, not $12. The final price is $64.80 and the effective saving is 46%, not 50%. Discount & Sale Price Calculator makes that arithmetic explicit with a step-by-step breakdown table so there is no ambiguity about which number each percentage applies to.

The Extra Stacked Discount field is optional. When left at zero the tool works as a straightforward percent-off calculator. When filled in it shows both individual savings and the combined effective rate — the single figure a customer or buyer actually needs.

Step by Step: Using the Calculator

1. Enter the Original Price: the pre-discount figure shown on the tag or listing.
2. Enter the Discount %. This is applied first.
3. Optionally enter an Extra Stacked Discount %: a second percentage applied to the price after the first reduction, not to the original.
4. Select a Currency symbol for the display. The maths is currency-agnostic; this controls the prefix only.
5. Read the Final Price, You Save, and Effective Rate cards. The breakdown table below them shows every deduction individually.

How the Stacked Discount Formula Works

Two sequential percentage reductions compound multiplicatively: final = original × (1 − d₁/100) × (1 − d₂/100). The effective single-step rate is 1 − (1 − d₁/100)(1 − d₂/100), which is always less than d₁ + d₂ when both are positive. A 50% + 25% stacked offer saves 62.5%, not 75%. The tool names this gap explicitly.

Limits and Rounding Behaviour

• Primary discount must be between 0% (exclusive) and 100% (inclusive). An entry of exactly 100% is valid and produces a final price of $0.00.
• Extra discount accepts 0–100%. If both discounts together would exceed 100% of the original, a validation message fires before any result is shown: "Combined discounts exceed 100% — check your values."
• All money figures are displayed at exactly two decimal places using toLocaleString with en-US grouping, so 1000 renders as 1,000.00. The underlying calculation uses full floating-point precision; rounding happens only at display time.
• The currency selector changes the symbol prefix only. No exchange rate is applied — the tool is currency-agnostic by design and the same percentage maths works for any denomination.