Why does the calculator say markup is undefined for my digital product?
Because markup is profit divided by cost, and with a cost of zero that is a division by zero, which has no answer. The calculator says undefined rather than inventing a number, while margin is still calculated normally.
What happens with a cost of zero
You sell a CV template or an e-book for 49. No stock, no shipping, so you type zero as the cost in the Profit margin calculator. The result:
Cost 0 and price 49.
Profit 49.
Margin 100%.
Markup: undefined, with a note explaining it is a division by zero.
A 100% margin makes sense: the whole price is profit. Markup asks 'how much did you add on top of what you paid?', and you paid nothing, so the question itself has no meaning. Some tools show 'Infinity' or an enormous number here, which misleads because it looks like a value you could compare.
Is your digital product really free to deliver?
Usually not. Some costs recur with every sale, even small ones:
- The payment gateway fee on each transaction.
- The platform's commission, if you sell through a digital products marketplace.
- Each sale's share of hosting or file delivery, if that is billed by usage.
Take those amounts for one sale from your statement and enter their total as the cost. If they come to 3.5 per sale, a price of 49 gives a margin of 92.86% and a markup of 1300%. Now markup has a value, and more importantly the margin reflects what actually reaches you.
What about the cost of making it?
The hours you spent designing the template, or a one-off fee to a designer, are not a cost per copy. Spreading them over an expected number of copies invents a figure that changes every time you sell more. It is clearer to keep the cost field for expenses that repeat with each sale, and to see when you recover the production cost by dividing it by the profit per copy: 1400 of production with 45.5 profit per copy means about 31 copies before you are back to even.
Another case: a free download
If you give away a file to build an email list, the price is zero and the cost is zero, and the calculator shows both margin and markup as undefined. That is correct: there is no sale here to measure. Judge that file by the later sales it brings, not with a margin calculator.
And to set a price that leaves a given margin after a platform's percentage commission, use the Selling-price calculator.
Common questions
Does 'undefined' mean I typed something wrong?
No, it only means the cost is zero. If that is what you intended, the result is correct.
Which figure should I use to compare my digital products?
Margin and profit in money. Markup turns into huge numbers when costs are tiny and does not help much with comparison.