Discount impact calculator
Discount & Sale Price Impact Calculator
See how much a sale really costs. This discount impact calculator shows your profit and margin before and after a discount, and how many extra units you need to sell to earn the same profit. It works well as a sale discount profit calculator and a margin with discount calculator for small business sellers on Etsy, eBay, Amazon, Shopify, or their own shop.
Calculator
Check the real impact of your discount
This discount impact calculator for ecommerce compares full-price and sale-price unit economics so you can see margin drop, profit loss, and the extra volume needed to keep profit flat.
Core pricing inputs
Use either discount percent or sale price. The last field you edit becomes the source of truth.
Display only. This does not convert between currencies.
All-in cost per unit - materials, labour, packaging, and a fair share of overhead.
Your normal selling price before any sale, coupon, or promotion.
Example: 20 means 20% off.
Edit this directly if you already know the promotional sale price.
Fees and shipping
Add marketplace, payment, fixed, and shipping contribution inputs for a more realistic sale discount profit calculator.
Example: marketplace commission or channel fee.
Example: card or marketplace payment processing rate.
Example: flat processing fee.
Use 0 if shipping is free to the customer.
What you actually pay to ship one order in this simple model.
Used to compare monthly profit before discount and the volume lift needed.
Results
Before and after the discount
Before discount
Your current full-price contribution per unit.
Regular price per unit
A$30.00
Profit per unit
A$17.45
Margin %
58.2%
After discount
Per-unit economics at the discounted sale price.
Sale price per unit
A$24.00
Discount %
20.0%
Profit per unit
A$11.90
Margin %
49.6%
Margin change
Margin moves from 58.2% to 49.6%, a loss of 8.6% percentage points.
Price cut per unit
A$6.00
Profit change per unit
-A$5.55
Shipping net per unit
A$0.00
Volume impact
Volume lift is based on actual profit per unit before and after discount, including platform fees, payment fees, fixed fees, and shipping difference.
Extra units needed
46.6%
Volume lift factor
1.47x
Break-even units / month
73.3
Monthly profit before discount
A$872.50
Monthly profit at same volume
A$595.00
Extra units / month needed
23.3
Short comment
At 20.0% off, your margin falls from 58.2% to 49.6%. You would need to sell about 46.6% more units to earn the same total profit as before.
Breakdown
Full price vs sale price side by side
| Metric | Before | After |
|---|---|---|
| Revenue per unit | A$30.00 | A$24.00 |
| Variable fees per unit | A$2.25 | A$1.80 |
| Fixed fee per unit | A$0.30 | A$0.30 |
| Shipping net per unit | A$0.00 | A$0.00 |
| Total contribution cost per unit | A$12.55 | A$12.10 |
| Profit per unit | A$17.45 | A$11.90 |
| Margin | 58.2% | 49.6% |
| Units needed vs current | 50 | 73.3 |
This margin with discount calculator for small business decisions compares contribution, profit, and margin before and after the sale so you can judge whether volume lift is realistic.
How this is calculated
How your current discount impact is calculated
This live walkthrough updates from your current inputs so you can see how sale price, profit per unit, margin drop, and break-even volume lift are built.
Open the live calculation walkthroughHide the live calculation walkthroughUses your current price, fee, shipping, and monthly volume inputs.
How it works
How this discount impact calculator works
A discount feels like a growth lever, but it can destroy profit quickly if volume does not rise enough. This tool uses standard discount maths to make sale-price economics easier to see.
A simple discount can erase more margin than expected
A sale discount profit calculator makes it clear that a simple 20% off promotion does not reduce profit by only 20%. Once fees and fixed selling costs stay in place, per-unit profit can fall much faster than the headline discount suggests.
Volume lift is often harder than it looks
Many sellers underestimate how many extra units they need to sell after a discount. This discount impact calculator for ecommerce uses actual per-unit profit before and after the sale to show the volume lift needed to keep total profit flat.
Small-seller maths, not enterprise retail assumptions
This margin with discount calculator for small business decisions is tuned to makers and marketplace sellers. It keeps the model simple but still accounts for platform fees, payment fees, fixed charges, and shipping contribution.
Why this matters
Many "how many extra units do I need to sell after a discount" examples ignore selling fees and shipping contribution. This calculator uses actual profit per unit before and after discount, which makes the volume-lift answer more useful for small sellers.
Use cases
When to use this sale discount profit calculator
Use it before you run a promotion, match a competitor, or send out a coupon code so the discount decision stays tied to real margin.
- Check the profit cost of a sitewide sale before you launch it.
- Test Etsy coupon codes before you send them to an email list or repeat buyers.
- Plan Black Friday, seasonal sales, or clearance events with realistic volume targets.
- Decide whether to match a competitor's discount without guessing at the margin hit.
FAQ
Discount and margin FAQs
Short answers to the sale-planning questions small ecommerce sellers ask before running coupons, promotions, or sitewide discounts.
What does this discount impact calculator do?
It shows how a discount changes your price, profit per unit, margin percentage, and how many extra units you need to sell to keep the same profit.
How do I calculate sale price from a discount?
Sale price equals regular price multiplied by one minus discount percent divided by 100. For example, 30 at 20% off becomes 24.
Why do I need to sell so many extra units after a discount?
Because each unit now earns less profit. If you cut margin in half, you often need about double the volume to earn the same total profit.
Can I use this calculator for Etsy, eBay, Amazon and Shopify?
Yes. Enter your own platform and payment fee percentages so the margin and profit numbers reflect your actual marketplace.
Does this include income tax or fixed overheads?
No. It focuses on per-product profit and margin before income tax and fixed costs. You can combine its results with a separate break-even calculator for a fuller business view.
What is a safe discount percentage?
It depends on your margin. This calculator lets you test different discounts and see the break-even volume for each instead of using a fixed rule.
Related tools
Connect sale planning back to pricing, tax, and break-even work
Discount decisions are stronger when they are connected to full product cost, tax-aware margin, wholesale pricing, and the sales volume your business needs overall.
Handmade Pricing Calculator
Build a profitable price from real costs and target margin.
Break-even Calculator for Makers
See how many units or how much revenue you need to break even.
Sales Tax / GST Margin Helper
See true margin after tax and solve for the right tax-aware selling price.
Wholesale vs Retail Calculator
Compare retail and wholesale profit, margin, markup, and discount sustainability.