Every December, Mama Tolu’s cake business runs the same promotion. Ten percent off everything.
The orders pour in. Her phone doesn’t stop ringing, and her oven runs until 2am for three weeks straight. In January she sits down with her notebook and discovers she made less money than in November.
She didn’t do anything wrong, exactly. She just never did the arithmetic.
Price changes are the decisions business owners agonise over most and calculate least. A discount feels safe and a price increase feels dangerous, yet the arithmetic usually points the other way. The reason is margin. A price change moves your profit per sale by far more than it moves your price. A small discount can demand a big jump in sales just to stand still, and a modest increase can survive losing a surprising share of customers.
This calculator shows how big those effects are for your own numbers. It pairs with the pricing strategy guide, which covers how to set and communicate prices.
Price change calculator
Defaults are illustrative placeholders. Replace them with your own figures.
Why the Numbers Surprise People
Take the default example. A ₦50,000 product costs ₦30,000 to deliver, leaving ₦20,000 of margin. A 10% price increase adds ₦5,000 to the price, which is a 25% increase in margin per sale. That’s why you can lose a meaningful share of sales and still earn the same profit.
King Pyrrhus beat the Romans and lost so many men doing it that his name became the word for a victory that costs too much. Mama Tolu’s December is a Pyrrhic sale.
Now run it the other way. A 10% discount removes ₦5,000 from the same ₦20,000 margin, which cuts what each sale earns you by a quarter. To make up for it, you need a third more sales. Many businesses run discounts expecting a lift in volume that never comes close, and end up busier and poorer at the same time. Mama Tolu knows the feeling.
The thinner your margin, the more extreme both effects become. A thin-margin business has the most to gain from a price increase and the most to lose from a discount. Funnily enough, most thin-margin businesses do the exact opposite under pressure, and I understand why. Discounting feels like doing something.
Fill In the Inputs Honestly
The calculator is only as honest as what you feed it.
Direct Cost per Unit
Include every cost that rises with each extra sale, such as materials, stock, delivery, payment processing fees, sales commission and packaging. Leave out costs you pay regardless of sales, like rent and salaries, because those belong in fixed costs. Getting this split wrong is the most common reason a pricing calculation misleads.
Units per Month
Use a normal month, and resist the urge to use your best one. Everybody remembers their December. If your sales are seasonal, run the calculator for a typical month and again for your peak.
Fixed Costs
These only affect the break-even figures. They leave the “same profit” comparison alone, because fixed costs stay put when the price moves. It’s also why a price decision should be judged on margin, whatever this month’s overheads look like.
Reading the Results
Sales needed for same profit is the number that matters most. For an increase, it tells you how many customers you can afford to lose. For a discount, it tells you how many extra customers you must win to justify it.
Break-even sales shows how many sales you need each month to cover fixed costs. A price increase lowers that number and makes the business sturdier in slow months. A discount raises it.
The verdict turns the result into one sentence you can take into a pricing decision. If it says a discount needs 40% more sales and you’ve never had a month anywhere near that, the discount is a loss wearing a promotion’s clothes.
Four Times to Use It
- Before any discount or promotion. Work out the extra sales it needs, then ask honestly whether the promotion will deliver them. Often the better answer is a smaller, better-targeted offer, or no offer at all.
- Before a price increase. Find out how many customers you can lose and still come out ahead. Most owners discover their tolerance is much higher than their fear.
- When your costs rise. If supplier costs or the exchange rate push up your direct costs, enter the new cost with a 0% price change to see how much profit you’re absorbing. Then find the price that restores it. The currency guide covers how FX exposure affects costs.
- When choosing between two price points. Run both and compare the break-even sales. The option with the lower break-even gives you more room when a month goes badly.
What the Calculator Can’t Tell You
It can’t predict how many customers will actually leave after a price increase, or how many a discount will actually attract. That depends on your market, your competitors and how well you explain the change. What it gives you is the threshold. If you lose fewer customers than the threshold, the increase paid off. If a discount attracts fewer than its threshold, it didn’t. Measure the real outcome against that number, ideally by asking customers and testing on new buyers first.
Revenue Is a Liar
Don’t judge a price change by revenue. A discount almost always raises revenue in the short term, because more sales come through the door, and it can still cut your profit while doing it. Revenue tells you how busy you were. Margin tells you whether it was worth it.
For customer acquisition decisions, pair this with the ad ROI calculator. A price increase raises your break-even cost per customer, which can turn an unprofitable ad channel into a profitable one.
Run It Before December
This December, Mama Tolu could run the numbers before the promotion. I’d bet her oven gets more sleep, and her notebook tells a happier story in January.
Pricing is one lever. The free 2-minute diagnostic looks at all four walls and tells you which one to pull first.
P.S. If your marketing spend is ₦1M or more a month, there’s a free 30-minute Leak Check waiting for you too. Discounts are a common culprit.
Mama Tolu’s story is illustrative. This calculator performs simple arithmetic on the figures you enter. Defaults are illustrative placeholders, not benchmarks, and it does not predict customer behaviour. This is general business information, not financial advice.
This article covers one part of a bigger system. Our guide to digital marketing in Nigeria shows how the four walls fit together, and the order to build them in.
