A discount can bring in more orders and still leave less money to cover the business’s fixed costs. Useful sales price analysis starts with the contribution per unit, rather than revenue alone.
The arithmetic is manageable. Agree which costs change with each sale, calculate what remains at the old and proposed prices, and work out the extra quantity needed to keep the same total contribution.
What number are you trying to preserve?
For this example, contribution means selling price less the stated variable cost per unit. It is not net profit. Your finance team should agree the relevant cost basis; a product purchase cost alone may leave out delivery, transaction fees or other costs that change with the sale.
Compare prices on the same basis and period. Keep VAT treatment, product units and cost assumptions consistent. If the discount changes delivery patterns, purchasing costs or service effort, update the calculation rather than treating the old cost as permanent.
Worked example: 10% off needs 34% more whole units
Take a fictional product selling at £50, with an agreed variable cost of £30. Contribution is £20 per unit. At 100 units, that leaves £2,000 before the costs excluded from this measure. All example figures exclude VAT.
Cutting the price to £45 is a 10% reduction. With the stated cost unchanged, contribution falls to £15 per unit. To retain £2,000, the calculation is £2,000 ÷ £15 = 133.33 units. If only whole units can be sold, you need 134.
That is 34 more units than the original 100. At 134 units, revenue is £6,030 and contribution is £2,010. The larger revenue number does not remove the need to sell the additional units, fulfil them and check that the cost assumptions still hold.
How do you use the calculation for another product?
Divide the old contribution per unit by the new contribution per unit, then multiply by the original quantity. This gives the theoretical quantity needed to retain the same contribution under those assumptions. Round appropriately for the unit you actually sell.
If the proposed contribution is zero or negative, this calculation does not produce a useful positive sales target. Stop and review the offer. Higher volume cannot repair a negative contribution per unit while those assumptions stay unchanged.
What should you check after changing the price?
Compare quantity, revenue and the approved contribution measure over suitable periods. Check working days, stock availability, promotions and customer mix. A product that was unavailable for half the earlier period does not give you a clean price comparison.
The price-change analysis demonstration shows how several trading measures and stock context can sit together. An observed change after a price adjustment is not proof that the adjustment caused it.
Where can automation help without choosing the price?
Automation can assemble the approved prices, costs and quantities, reproduce the calculation and flag missing inputs. Keep the assumptions and refresh time visible. A person still decides whether the extra volume is plausible and whether the commercial trade-off makes sense.
Use the order-profitability checks to keep incomplete costs visible. If the decision becomes a proposed website update, a separate price-approval step should record what was authorised. A report result should not silently become a live price change.
Test the calculation manually for a discount, a price increase, a changed cost and a zero-contribution offer. Keep a working spreadsheet or other agreed manual route available if the automated report cannot run.