Discount Impact on Margin Calculator

No. A discount cuts the selling price, while margin is computed from the discounted selling price, so the relationship is not linear. Example: COGS of Rp100,000 and a list price of Rp200,000 give an initial margin of 50%. With a 20% discount, the selling price becomes Rp160,000 and margin = (160,000 − 100,000) ÷ 160,000 = 37.5%. Margin falls 12.5 points (from 50% to 37.5%), not 20 points. At a 50% discount, the selling price becomes Rp100,000 and margin becomes 0% — the entire margin is gone even though the discount is “only” half the price.

Three steps: (1) selling price = list price × (1 − discount%), (2) profit = selling price − COGS, (3) margin = profit ÷ selling price × 100%. Example: COGS Rp100,000, list price Rp200,000, 20% discount. Selling price = 200,000 × 0.8 = Rp160,000. Profit = 160,000 − 100,000 = Rp60,000. Margin = 60,000 ÷ 160,000 × 100% = 37.5%. Mode 1 of the calculator above shows all three steps automatically.

First determine the minimum selling price = COGS ÷ (1 − target margin), then maximum discount = (1 − minimum selling price ÷ list price) × 100%. Example: COGS Rp100,000, list price Rp200,000, target margin 30%. Minimum selling price = 100,000 ÷ 0.7 = Rp142,857.14. Maximum discount = (1 − 142,857.14 ÷ 200,000) × 100% = 28.57%. Any discount above 28.57% pushes margin below 30%. Mode 2 computes this along with the minimum selling price.

Four common traps: (1) assuming margin falls by the discount percent — in reality the drop is in margin points and is not linear; (2) stacked discounts apply to the already-discounted price, they are not added (20% then 10% is not 30%, it is 28%); (3) comparing margin against the list price instead of the discounted selling price; (4) forgetting that non-COGS costs (such as shipping or service fees) also erode the effective margin when absorbed by the seller.

The percent-off calculator computes the discount itself — price after discount, stacked discounts, reverse, and two-promo comparison — without considering COGS or margin. This calculator takes it further: from COGS + list price + discount it computes the selling price, margin after discount, the maximum discount that hits the target margin, and the list price needed for a planned discount. Use both in sequence: compute the promo there, measure its impact on margin here.

The gross margin calculator computes margin from sales and COGS — with no discount concept at all. This calculator adds the discount dimension: margin is computed from the selling price after discount, with a maximum-discount mode from a target margin, a two-level discount comparator, and a list-price solver from a planned discount. If you do not discount, the gross margin calculator is enough; if you run promos, use this one.

That is the standard definition of gross margin: gross profit divided by sales. Computing from COGS is called markup, and the figure is always larger. Example: COGS Rp100,000, selling price Rp160,000. Margin = (160,000 − 100,000) ÷ 160,000 = 37.5%, while markup = (160,000 − 100,000) ÷ 100,000 = 60%. Mixing the two makes a “40% margin” target read as a 40% markup, which is actually only a 28.57% margin.