How to measure coaching effectiveness in your business
A decision can be clearer even while its financial consequences are still unknown.

A useful review of business coaching records the question you brought, the step you chose, what you tried and what you learned. Those answers give you a basis for deciding whether to act on your own, work through another choice with the coach or get help doing the work.
What were you trying to decide or change?
The question you brought gives you something to review against. A wish for more clients calls for a different discussion from deciding which work to stop selling. If the question became clearer during the conversation, use that clearer version. You do not have to pretend you arrived with a precise target.
My first coaching conversation ends with a step you choose and what you want to notice or learn from trying it. The written summary records what we agreed. Returning to it can help you distinguish what was discussed from what you later expected the conversation to deliver.
Some questions may be settled in the conversation. Deciding to postpone an idea, and understanding why, can be the result you needed. It does not have to become another project to count as a useful choice.
What happened when you tried it?
What happened afterwards can show whether the proposed step was useful in your business. Keep the account close to the work: what you did, what response you received and what remains uncertain.
In a hypothetical example, an owner wants to find out why a new service attracts interest but no commitments. During a coaching conversation, they choose to speak with two people who had asked about it and then stopped replying. Both conversations happen, and the owner learns that the proposed delivery timing does not fit either buyer.
No sale has resulted. The owner nevertheless has information that was missing before and a decision to make about the offer. That is different from recording two conversations as proof that the service will sell. If the owner never speaks with either person, the question remains open.
The observation you need depends on the step you chose. A decision about keeping evenings free might be reviewed against the actual calendar. A decision about an offer might need a customer's response. Counting completed tasks will not explain their usefulness on its own.

Which result came from the coaching?
A change after coaching does not, by itself, establish that coaching caused it. A new client could also reflect work already in progress, a recommendation or a change in the buyer's circumstances.
The International Coaching Federation's evaluation guide distinguishes a client's reaction, learning, behaviour and results. That distinction helps keep several questions visible: was the conversation useful, did it change what you understood or did, and what happened in the business afterwards?
You can describe the contribution without putting a return-on-investment figure on it. For example, the conversation may have helped you notice an assumption and choose a different question to ask. The answer you received from the customer is a further observation. Neither proves how the business would have developed without coaching.
What if the next step did not happen?
An untried step calls for a discussion about what prevented it. It is too early to judge the result of a change that never reached your working week.
Perhaps the step needed time you had already promised to a client. Perhaps it depended on information or agreement you did not have. The next conversation can revisit whether the proposed action was workable, whether it still addresses your question and what needs to change before you can try it.
That review includes the coaching itself. If the conversation repeatedly leaves you with a plan you cannot use, say so. Another session should have a reason beyond returning to the same unfinished list.
Would another coaching conversation help?
Another conversation has a purpose when your review identifies a choice you want help working through. In the hypothetical example, the owner could use it to weigh whether to change delivery after hearing the buyers' timing objections. If the owner already knows what to change and can try it, they have a reason to act before booking again.
If the step was never tried, the unanswered question is what prevented it. Resolving a time or information gap may let you proceed on your own; repeated difficulty choosing a workable step is something to raise with the coach. If you have made the decision and need help doing the work, the difference between coaching and consulting matters.

In my coaching, the first conversation stands on its own. There is no fixed programme or minimum number of sessions, and you decide whether to continue. A useful starting point for that decision is: what remains unresolved, and what would you like another conversation to help you decide?