The product-market fit survey asks product users how they would feel if they could no longer use it. The share who answer "very disappointed" is a demand signal: it shows whether there is a group for whom the product is already indispensable. The calculator compares that share with the 40% benchmark, a product market convention, and shows the confidence interval to tell you when the sample is not yet enough.
How to use
- Send the questionnaire to people who have really used the product recently.
- Count the very disappointed, somewhat disappointed and not disappointed answers; note separately those who no longer use it.
- Enter the counts and read the "very disappointed" share with its 95% interval.
- Compare with the 40% benchmark: above, below or still inconclusive.
- Read the open answers from the "very disappointed" group to understand who the product already works for.
What each field asks for
| Field | What to enter |
|---|---|
| Product name (optional) | Used in the ready-to-copy questionnaire. |
| Very disappointed | "Very disappointed" answers to the main question. |
| Somewhat disappointed | "Somewhat disappointed" answers. |
| Not disappointed | "Not disappointed" answers. |
| No longer use it (optional) | Left out of the count: the question applies to current users. |
Example
A fictional personal finance app, Organiza+, sent the survey to people who used the product in the last two weeks. Of the 140 valid responses, 72 said "very disappointed", 48 "somewhat disappointed" and 20 "not disappointed"; another 11 people no longer use it and were left out. The very disappointed share is 51.4%, with a 95% interval from 43.2% to 59.6%: above 40% even at the low end.
When to use
- Once a group of people uses the product with some frequency, to measure whether it is already indispensable.
- Before investing in acquisition, to check that there is a core of users who would miss the product.
- To compare segments and find out which audience the product works best for.
- To track, cycle after cycle, whether improvements raise the very disappointed share.
Frequently asked questions
What is the product-market fit survey?
It is a short questionnaire whose main question is how the person would feel if they could no longer use the product. The "very disappointed" share shows how indispensable the product already is for its users.
Where does the 40% benchmark come from?
It is a product market convention, observed in companies that grew sustainably after passing that mark. It is not a statistical law: use it as a signal and confirm it with retention and recurring use.
Who should answer?
People who have really used the product recently, for example twice in the last two weeks. Someone who only signed up cannot say whether they would miss it. Those who answer "no longer use it" are left out of the count.
How many responses do I need?
With fewer than 40 valid responses, the confidence interval is too wide to compare with the benchmark. The calculator shows the interval so you know when the sample already separates the result from 40%.
What should I do with a result below 40%?
Read the profile and the benefit mentioned by the "very disappointed" group: it shows who the product already works for. Focus improvements on that audience and on the main benefit, and repeat the survey after each cycle.
How is it different from NPS?
NPS measures willingness to recommend; the product-market fit survey measures how much the person would miss the product. The latter is more useful early on, to find out whether real demand exists, while the former tracks the loyalty of an established base.