Free tools
The free Price Lab — what is a price rise worth?
For food and retail shop owners thinking about raising or cutting prices. Enter a few products and a percentage, and see the change in monthly profit and how many sales you could lose before the rise stops paying.
4 min read · Updated October 9, 2026
The free Price Lab tests a price change on the products you type in, before you touch a real price. It is free, needs no account, and runs in your browser, so nothing you type is sent anywhere.
How do I know if a price increase is worth it?
Compare the extra profit per sale with the sales you might lose. A rise pays as long as you lose fewer sales than the share the tool shows. A burger earning $4.00 that rises 5% earns $4.48, so you could sell 10.6% fewer and make the same profit. Losing fewer sales than that means the rise has paid.
Use it
- Pick your currency. It starts on US dollars, and the choice is remembered on your device.
- For each product, enter its price now, its cost and how many you sell a month. A name is optional. Start with your best sellers; you can add up to eight.
- Enter the price change to test as a percentage. Use a minus sign, such as -10, to test a price cut.
It shows:
| Result | What it means |
|---|---|
| Extra profit a month | What the change adds if you keep selling the same amount |
| You could sell this many fewer | For a rise: the share of sales you can lose and still earn what you earn today |
| You would need to sell this many more | For a cut: the extra sales needed just to stand still |
| Each product | The old and new price, and the profit on one sale before and after |
What counts as the cost?
What one more sale costs you, and nothing else.
- For food, that is the ingredients and packaging in one serving. The yield estimator works out the ingredient cost after trimming and cooking loss.
- For goods you resell, it is what you paid the supplier for one. If you buy by the box, the pricing calculator splits the box cost into a cost per piece.
Leave out rent, wages and bills. They stay the same whatever you charge, so they don't change the answer.
If your prices include sales tax, take the tax out of the price first. The tax was never yours, and counting it makes every profit look bigger than it is.
How the "sell fewer" number is worked out
Today's monthly profit divided by the new monthly profit gives the share of today's sales you need to earn the same.
600 burgers × $4.00 = $2,400 a month
At +5%, each earns $4.48, so $2,400 ÷ $4.48 = 536 burgers
536 ÷ 600 = 89.4% of today's sales, so you could sell 10.6% fewer
With several products, the tool works this out on their total, as if every product lost the same share of sales.
Is this the same as Price Lab in the app?
It is the same idea, done by hand. Price Lab in the Kasenso app uses your real sales: it reads what you sold and what each sale cost from your records, so you don't type anything in, and it works for food and retail products alike. You can set a different change for each product and see your profit after expenses.
Frequently asked questions
What does the free Price Lab calculate?
It takes a few products, each with a price, a cost and monthly sales, and applies one price change. It shows the change in monthly profit, the profit on each sale before and after, and how many sales you could lose, or would need to gain, to end up with the same profit as today.
Does it work for retail shops?
Yes. For goods you resell, enter what you paid the supplier for one as the cost. The arithmetic is the same for a bag of rice, a phone charger or a plate of noodles: price minus cost is the profit on each sale.
How much should I raise my prices?
There is no single right number. Test a modest rise of 3% to 5% first, and check that the share of sales you could lose is more than you expect to lose. Your regulars notice the items they always buy most, so consider moving the items around your best seller instead.
Why does a price cut need so many more sales?
The cost of each item stays the same, so every cent you cut comes straight off your profit. A burger earning $4.00 that is cut 10% from $9.50 earns $3.05, so you need about 31% more sales just to make the same profit.
Why doesn't it include rent and wages?
They stay the same whatever you charge for each item, so a price change doesn't move them. The tool shows the change in profit before those costs. The break-even calculator works out how much you need to sell to cover them.
Is my data saved or sent anywhere?
No. It is worked out in your browser and gone when you close the page.
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