Everything you need to actually start a business.
47 working tools across the 10 stages of building a company — from deciding whether to start, to working out what it is worth. Every number shows its source and its year.
- 47
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- stages
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- sources cited
- £0
- forever
Every business that exists was, at some point, somebody sitting down and starting.
with a hunch, and no idea whether it survives contact with a spreadsheet.
it stops being an idea and starts being a thing with a price on it.
the lights are on, the till is open, and it is simply a business.
Set this up once
Where you are changes the legal form, the funding sources and the filing deadlines. What you sell changes which numbers matter. Tell the toolkit both and every tool adjusts.
From “should I?” to “what is it worth?”
If you only use a few
The tools that change the most decisions.
quizFounder-market fit score
The strongest published predictor of founder success is not personality, it is knowing your market. Score yourself on six dimensions.
referenceBase-rate buster
The things founders believe, next to what the published data actually says, and what each study really measured.
worksheetMarket evaluation worksheet
The ten questions that turn an idea into an opportunity. Answer each one, say how confident you are, and write down the test that would settle it.
quizOpportunity scorecard
Five characteristics separate an opportunity from an idea: value, risk-adjusted profit, fit, durability and financeability. Score yours against all five.
calculatorBreakeven calculator
How much you must sell before you earn anything, and what each sale is worth after that. The first number every founder needs.
worksheetThe five questions
Five answers you must be able to give to anyone who asks, in a sentence each. If you cannot, you do not yet have a business model.
Where this comes from
The method
HBR's Entrepreneur's Handbook (Harvard Business Review Press, 2018). Thirteen chapters and four appendices, distilled. It supplies the questions worth asking and the order to ask them in, which has not dated.
The current numbers
Thirteen researched supplements written in September 2026, covering what the book skips entirely, which is sales, marketing, hiring, operations, unit economics and SI, and refreshing what had aged, which is funding, law, product-market fit and exits.
How to read a number here
Every benchmark carries its source and year. Business data ages fast, so a 2026 figure is a starting point for your own measurement, never a target to copy.
General guidance only. Nothing here is legal, tax or investment advice, and anything touching company structure, tax, securities or selling a business needs a qualified professional in your own country.
Stuck on something specific?
Ask the adviser. It answers only from the handbook and the 2026 research, tells you which source each answer came from, and says so plainly when the research does not cover your question.