Why profit can fall faster than price
A price discount reduces revenue while many order costs remain unchanged. Product cost, packaging and a fixed fulfillment charge do not automatically fall with selling price. Percentage payment and platform fees do decline because this model applies them to actual discounted revenue. The remaining profit can therefore fall by a much larger percentage than the advertised discount. Comparing the before-and-after profit amounts is more informative than considering the discount percentage alone.
The formula
Keep currency, units and time periods consistent. Percentage inputs use percentage points (enter 5 for 5%). Results are rounded only for display; tiny nonzero values may use scientific notation. Undefined ratios are shown as unavailable.
At a $100 price and $60 fixed per-order cost, with no percentage fees, profit is $40. A 20% discount produces an $80 selling price and $20 profit. To replace the $4,000 earned on 100 full-price orders, you need 200 discounted orders: a 100% lift. A 25% lift would produce just $2,500.
Establish a useful baseline
Enter the regular selling price and variable costs for a representative order. Baseline orders define the total contribution the promotion must replace. Use the same period and product mix when estimating the expected volume lift. This calculator does not include a separate advertising field; if a stable acquisition expense belongs in your per-order economics, include it consistently within other variable cost. If the promotion needs a new fixed campaign budget, review that additional expense separately rather than assuming the volume comparison covers it.
Break-even sales volume
The calculator divides baseline total profit by discounted profit per order to find the order count needed to replace it. Required order counts round upwards because you cannot fulfill a fraction of an order. The percentage lift uses the unrounded economic ratio so you can inspect the underlying relationship. If discounted contribution is zero or negative, more sales cannot replace a positive baseline contribution under these assumptions. The required-volume result is then unavailable rather than an arbitrarily large number.
Maximum discount and selected margin
Break-even discount solves for the price reduction that leaves zero contribution after the entered variable expenses. Maximum discount for the selected margin reserves your chosen profit percentage of discounted revenue. These are different boundaries. A negative maximum-discount result indicates the regular price already fails that boundary and would need to rise under the model. It does not mean you have room for a promotion. A one-hundred-percent discount also removes the revenue denominator needed for a meaningful margin percentage.
Compare expected lift with required lift
Expected promotional profit multiplies discounted contribution by baseline orders and your assumed volume increase. The comparison tells you whether that assumption replaces the baseline profit. It does not estimate how much demand a discount will create. A promotion can attract customers who would have purchased at full price, shift sales from a later period, or change the basket mix. These effects are outside the simple model, so evaluate actual incremental sales and contribution when reviewing the promotion.
Sensitivity and operational limits
The discount table shows several common percentages alongside the current calculation’s baseline. Each row keeps the entered per-order costs and order assumptions fixed. In practice, more orders can change pick-and-pack costs, overtime, stock availability, returns and shipping charges. Review those changes before interpreting a required sales lift as operationally possible. Use Product Pricing to work backwards from a planned promotion to a list price, and Ecommerce Profit when you also need explicit acquisition expenses and monthly overhead allocation.
Method and reference sources
Method and content checked 2026-09-20. These sources provide background, not endorsement or professional certification. The formula and limitations above define this calculator.
- SBA — Break-even pointContribution, variable costs and fixed-cost break-even context; tool-specific extensions are explained above.
Frequently asked questions
Can higher order volume offset a discount?
Only when discounted orders still make a positive contribution. The required order count replaces baseline profit; it does not predict whether customers will buy enough additional units.
What is a worked example for Discount Profit?
At a $100 price and $60 fixed per-order cost, with no percentage fees, profit is $40. A 20% discount produces an $80 selling price and $20 profit. To replace the $4,000 earned on 100 full-price orders, you need 200 discounted orders: a 100% lift. A 25% lift would produce just $2,500.