The Pricing Mistake That Quietly Costs Small Businesses Thousands

A supplier tells you the trade works on 30%. You take your cost, add 30%, and get on with it.

You now have a 23% margin. You believe you have 30%. On a business turning over 200,000 a year that gap is around 14,000 of profit that was never priced in, and nothing about your books will make it obvious.

The two formulas

markup = (price - cost) / cost   x 100
margin = (price - cost) / price  x 100

Same numerator. Different denominator. That is the whole difference and it is enough to break a pricing model.

Buy at 60, sell at 100. You made 40.

• Against your cost of 60, that is a 66.7% markup
• Against your price of 100, that is a 40% margin

Both correct. Both describing the same sale. Not interchangeable.

Why it stays hidden

Nothing breaks. You are still profitable, just less profitable than you think, and consistently so. There is no month where the number looks wrong, because it is wrong every month by the same proportion.

The error usually surfaces at the worst moment: when you model growth, take on a bigger contract, or try to work out why a busy year did not produce the cash you expected.

The fix is one line

To hit a target margin, divide by (1 minus the margin). Never multiply by (1 plus it).

For a 40% margin on a cost of 60:

60 / (1 - 0.40) = 60 / 0.6 = 100     correct
60 x 1.40       = 84                 wrong, that is a 28.6% margin

Values worth memorising

Markup	Margin	Multiply cost by
25%	20%	1.25
33.3%	25%	1.333
50%	33.3%	1.5
66.7%	40%	1.667
100%	50%	2.0
150%	60%	2.5
233%	70%	3.333

If you remember one row, make it this: doubling the cost gives a 50% margin, not 100%. That single fact prevents most of the errors.

Margin has a ceiling, markup does not

Margin is profit as a share of price, so it can approach 100% but never reach it. That would mean the goods cost nothing.

Markup has no upper limit at all. Buy for 10, sell for 100, and the markup is 900%.

This is why software and digital products are always discussed in margins. Markup figures on a near-zero cost become absurd and stop conveying anything.

Discounting eats margin much faster than revenue

Here is the part that catches people out even after they have the formulas straight.

On a 40% margin, a 10% discount does not cost you 10% of your profit. It costs a quarter of it.

	Full price	10% off
Price	100	90
Cost	60	60
Profit	40	30

Revenue fell 10%. Profit fell 25%.

At a 20% margin the same discount halves your profit. To stand still you would need to sell twice as many units, which usually means twice the packing, twice the support and twice the returns for the same money.

Which is why “we will make it up on volume” needs the arithmetic doing before anyone commits to it, and why thin-margin businesses discount so cautiously.

Gross margin is not profit

Everything above is gross margin, covering only the direct cost of goods. It does not include rent, wages, software, insurance, marketing or your own time.

A healthy gross margin and a loss-making business are entirely compatible, and it is a common shape for a small retailer. Net margin is what survives everything, and it is usually far smaller than people expect. Supermarkets typically run on 2 to 4%.

So work out gross margin first, then check whether the resulting volume actually covers your fixed costs. Pricing that ignores the second step is how businesses grow their way into trouble.

Always calculate excluding tax

Sales tax and VAT are collected on behalf of the government, not earned. Including them inflates both figures and makes the business look healthier than it is.

Strip the tax out first with the VAT calculator, then run the numbers.

Fixing it retrospectively

If you have been pricing on markup while believing it was margin, you have two options and both are uncomfortable: raise prices, or accept the lower margin knowingly.

The second is a legitimate choice. Plenty of businesses run on thinner margins deliberately. The problem was never the number itself, it was not knowing what the number was.

Run your actual figures through the markup and margin calculator before deciding which.