Margin and Markup Calculator

Same profit, different denominator

Margin and markup describe the identical dollar of profit. They differ only in what you divide it by.

• Gross margin = profit ÷ selling price
• Markup = profit ÷ cost

Buy an item for $60 and sell it for $100. The profit is $40 either way. As a share of the $100 the customer paid, that is a 40% margin. As a share of the $60 you paid, it is a 66.7% markup. Nothing about the transaction changed; only the question did.

Because the selling price is always larger than the cost on a profitable sale, the denominator on the margin side is always larger — so markup is always the bigger number. That single fact is why swapping one for the other is so dangerous. Nothing breaks. No error appears. You simply price lower than you meant to, on every unit, for as long as the mistake survives.

The two conversions are worth memorising, because they are the whole subject:

• markup = margin ÷ (1 − margin)
• margin = markup ÷ (1 + markup)

The trap: a 40% markup is not a 40% margin

Here is the mistake, in the exact form it usually arrives. A buyer decides the business needs a 40% margin. The cost is $60. They multiply by 1.40, get $84, and put it on the shelf.

That $84 price yields $24 of profit on $84 of revenue: a 28.6% margin. The target was 40%. They are eleven and a half points short and have no reason to suspect it, because the number they typed and the number they wanted were both "40".

The correct price for a 40% margin on a $60 cost is $100 — a 66.7% markup. The gap between $84 and $100 is not a rounding difference. It is sixteen dollars of profit per unit, which on a product doing a thousand units a month is $16,000 a month walking out of the door with a smile.

The error compounds in the other direction too. A distributor quoting "50% markup" is describing a 33.3% margin. A supplier promising "you can make 100% on this" means the price is double the cost, which is a 50% margin. Whenever someone states a percentage without saying which base it sits on, the number is ambiguous and the difference is always money.

Why a 100% margin cannot exist

A margin of 100% would mean the profit equals the entire selling price, which requires the item to have cost you nothing. Above 100% is worse — it requires a negative cost, a supplier who pays you to take the goods.

This is not a pedantic point, because the arithmetic actively breaks. Price is calculated as cost ÷ (1 − margin), so a margin of 100% divides by zero. Calculators that do not check for it return infinity or a blank, and the person using it assumes the tool is broken rather than the request. This one rejects the input and explains why: if you are reaching for a number above 100%, you are thinking in markup.

Markup has no ceiling at all. A 100% markup means doubling the cost, which is completely ordinary. Fashion apparel routinely runs at 100-150%. Restaurant wine lists frequently hit 300%. Prescription eyewear can exceed 1,000%. Every one of those figures is a normal markup and none of them is possible as a margin — a fact worth remembering the next time a headline reports an "800% margin" on something.

What belongs in cost of goods sold

Gross margin is only as honest as the cost you feed it. Cost of goods sold should include everything that varies directly with making or acquiring the unit you sold:

• The purchase price from the supplier, net of any volume rebate you actually receive.
• Inbound freight and import duty — landing the goods is part of acquiring them.
• Direct labour and materials, for anything you manufacture or assemble.
• Packaging that ships with the product.
• Payment processing and marketplace commission, if you want a margin that reflects reality rather than a textbook.

What does not belong: rent, salaries for people who are not making the product, software subscriptions, advertising, and your own salary. Those are operating expenses. They are real, they are often larger than COGS, and they are exactly what stands between gross margin and money in your account — but they belong on the line below, not inside the cost of the unit.

Two traps in particular. The first is forgetting inbound freight, which is easy when the invoice arrives separately from the goods and can quietly consume five to fifteen points of margin on heavy or bulky items. The second is including outbound shipping you charge the customer, which inflates both sides of the calculation and makes low-margin products look healthier than they are.

Retail, wholesale and SaaS run on different numbers

"Is my margin good?" has no answer without a sector. Gross margin is not a measure of how well you negotiate — it is a structural property of the business model, and it is meaningful only against comparable businesses.

The SaaS row deserves a note, because it is where gross margin gets abused most often. Software COGS is hosting, third-party API costs, payment fees and the customer support and onboarding staff needed to keep accounts running. It is not sales, not marketing and not engineering. A company reporting 90% gross margin has usually pushed support costs into operating expense; one reporting 60% is either infrastructure-heavy or is honestly counting a services component. Both numbers can be defensible, and neither is comparable to the other without knowing what went into the cost line.

A discount costs far more than the discount

Discounts feel like they come out of revenue. They come out of profit, and profit is a much smaller pool.

Take a product priced at $100 with a $70 cost — a 30% margin and $30 of profit. Offer 10% off and the price becomes $90 while the cost stays at $70. Profit is now $20. You gave away 10% of the price and a third of the profit. The general rule is that the share of profit lost equals the discount divided by the margin, which is why the same 10% discount is survivable at a 60% margin and lethal at a 12% one.

The volume required to compensate is the part that surprises people. To earn the same $30 of total profit at $20 per unit, you have to sell 50% more units — not 10% more. And those extra units carry their own picking, packing, shipping and support costs, so in practice the true break-even volume is higher still.

There is also a hard ceiling. Once the discount reaches the margin, profit is exactly zero, and every unit beyond that is a loss you are financing. On a 30% margin, a 30% discount is the floor. This is why a blanket "25% off everything" sale is dangerous across a mixed catalogue: on the high-margin lines it costs a slice of profit, and on the thin ones it sells below cost.

When your cost goes up, raise the price by the same percentage

A supplier raises your cost from $60 to $66. The instinct is to add $6 to the price and move on. That protects the profit per unit — you still make $40 — but it silently drops the margin from 40% to 37.7%, and it does nothing about the fact that the extra $6 of working capital is now tied up in every unit sitting in your warehouse.

To hold the margin, the price has to rise by the same percentage as the cost. Since price = cost ÷ (1 − margin), the price is a fixed multiple of the cost: a 10% cost increase requires a 10% price increase, from $100 to $110, at any margin level. The tool computes this directly, and also shows what happens if you absorb the increase instead — with the cost at $66 and the price held at $100, the margin falls to 34%, six points gone.

Six points sounds small until you compare it to net margin. A retailer working on a 6% net margin who absorbs six points of gross margin has not lost a fraction of the profit — the profit is gone.

Gross, contribution and net are three different margins

Gross margin is the first line, not the last. Three margins get used interchangeably and they answer three separate questions:

• Gross margin — price minus the cost of the goods. It tells you whether the product itself is viable and whether the pricing can absorb a discount.
• Contribution margin — price minus every cost that varies with the sale: goods, commission, payment fees, freight out. It tells you how much each extra sale contributes toward the fixed costs, which is the number that matters for break-even and for deciding whether to accept a marginal order.
• Net margin — what is left after everything, including rent, salaries, marketing and tax. It is the only one that answers "am I making money".

The distance between them is where businesses quietly fail. A 40% gross margin sounds comfortable; if operating expenses run at 30% of revenue and tax takes another 6%, the net margin is 4%, and a single point of gross margin lost to discounting removes a quarter of the profit. Set the overhead and tax fields in the calculator to your real figures and the gross number stops being reassuring — which is the point.

Privacy

Every figure stays in your browser. Nothing is uploaded, nothing is logged and there is no account. That matters more here than on most calculators, because what you type is your supplier pricing, your cost base and the margins you would not paste into a form belonging to a stranger.