Free tool · no sign-up
How deep can
your sale go?
One product’s price and costs. See the discount at which each sale stops paying for itself, and how many more units your discount has to sell to leave the same money.
Break-even discount
49%
Deeper than this, every unit sold loses money. At full price a unit leaves €19.76 (40% of the price).
- At 25% off, a unit leaves
- €9.82
- Share of the margin given away
- 50%
- Extra units needed to leave the same money
- +101%
| Off | A unit leaves | Extra units needed |
|---|---|---|
| 10% | €15.78 | +25% |
| 15% | €13.79 | +43% |
| 20% | €11.80 | +67% |
| 25% | €9.82 | +101% |
| 30% | €7.83 | +152% |
| 40% | €3.85 | +413% |
| 50% | −€0.12 | loses on every unit |
01 / How it is worked out
The arithmetic, in the open
A unit leaves its price without VAT, less the cost of the product, your shipping and packaging, and the payment fee (taken on what the customer pays). That is what it contributes towards ads and fixed costs.
The sale price is run through the same sum. The break-even discount is where what a unit leaves reaches zero. The extra units needed is the full-price contribution divided by the sale contribution: sell that many times as many units and the sale leaves the same money as no sale at all.
Ads and fixed costs are left out on purpose — they do not change with the discount, and a sale has to cover them either way.
02 / Questions
What people ask with it
Why does a 25% discount need far more than 25% more sales?
Because the discount comes out of the margin, not out of the price. The goods, the shipping and most of the fee cost the same at the sale price, so a quarter off the price can take half or more of what each unit leaves. The units have to make that up.
Where does VAT come into it?
In Europe and the UK the price a customer pays includes VAT, and it is not the shop’s money. A discount lowers the VAT owed along with the price, so the tool takes VAT out first and measures the giveaway in the shop’s own money.
Is a sale below break-even always a mistake?
Not always. A sale that loses money per unit can still win customers who come back at full price. The tool shows the price of that decision; whether it is worth paying is the shop’s call.
How is this different from what Profflow shows on a connected store?
Here you type one product’s figures. On a connected store Profflow reads every order, the cost of every product and every discount code, and shows what each promotion actually gave away and whether the extra volume paid for it.
03 / More free tools
The other questions, answered the same way
Profit calculator
What a month keeps after ads, fees, returns, goods and shipping.
Use it →Break-even ROAS
The ROAS below which an ad loses money on every order.
Use it →Shopify fees
What Shopify, the payment providers and the apps take from a month’s sales.
Use it →Price calculator
What to charge so a unit keeps the margin you want, after VAT, goods, shipping and fees.
Use it →Free-shipping threshold
The order value above which free shipping still earns the margin you want.
Use it →P&L template
A monthly P&L to download — sales down to net profit, for Google Sheets or Excel.
Use it →Store check
What a store’s own public pages show about its prices and stock.
Use it →
See it on your own store.
This is an estimate from the figures you typed. A connected store is measured order by order — read-only, in about ten minutes.