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As of 13 August 2026, AI can calculate your average deal size.
Most people should do this themselves; the prompt is on this page.
Can you do it?
5 minutesto a draft.
15 minutesto something you’d act on.
Cost, all in£0
Skill neededchat-fluent
Who has to check ityou
What the alternative costsNo comparable alternative price is provided in the supplied tool data.
If this goes wrong: you use an average based on the wrong stage, period or currency and make a poor internal comparison, which can be corrected by rerunning the calculation with the right rows.
What to actually do
Do it yourself
The route this page recommends
A chat interface, chat-fluent skill, and roughly 15 minutes until you can act on the result.
How to actually do it
- Open your CRM report or spreadsheet and decide whether the calculation covers closed-won deals, all opportunities or another defined group.
- Set the date range, currency and deal value field, then remove or label duplicates, cancellations and deals with missing values.
- Export or copy the relevant rows, including deal ID, stage, close date, currency and deal value, and remove customer personal data that the calculation does not need.
- Paste the data into a chatbot with the supplied prompt, replacing the bracketed rules with your chosen stage, dates, currency, field and rounding.
- Compare the reported included deal count and total against the filtered CRM report, then recalculate total deal value divided by included deal count in your spreadsheet.
- Record the result with its definition, date range, currency and exclusions before using it in a pipeline report or sales discussion.
Prompt
Calculate my average deal size from the deal data below. First state the definition you are using: total deal value divided by the number of included deals. Use only deals that match these rules: stage = [for example, closed won], date range = [start date] to [end date], currency = [currency], and deal value field = [field name]. Exclude blank values, duplicated deals, cancelled deals and deals outside the rules. If the data contains multiple currencies, stop and ask me to convert them rather than combining them. Show the included deal count, the total deal value, the formula, the result rounded to [number] decimal places, and a short list of excluded rows with the reason for each. Do not estimate missing values or invent any data. Deal data: [paste CRM export or table here]
Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.
Use a tool built for this
Second choiceHand it to a person
The distant thirdA person who owns the outcome does this end to end, worth it when the failure is dear.
What it gets wrong
- AI cannot decide whether your business means closed-won average, average open opportunity value or another measure without your definition.
- AI cannot repair inconsistent currency, duplicate records or incorrect CRM stages unless you identify the issue or provide rules.
- AI cannot know whether a one-off unusually large deal makes the mean misleading for your sales planning.
- AI cannot keep the result current when your CRM data changes unless you rerun the calculation or connect a suitable reporting workflow.
Even on a YES, the friction has a name: judgement under ambiguity and context depth.
How we scored this
Five axes, each scored nought to two by hand: ten means AI carries the task cleanly, and the thresholds that turn a total into YES, PARTLY or NO are published in the methodology. Each axis name links to its definition.
| Axis | Score (0–2) |
|---|---|
| Output | 2 |
| Inputs | 2 |
| Verification | 2 |
| Liability | 2 |
| Effort delta | 2 |
| Total | 10 / 10 |
The methodology and its thresholds are published in full.
FAQ
- Can ChatGPT calculate my average deal size?
- Yes. Give it a clean list of deal values and state the stage, date range and currency, then check its count and total against your CRM.
- What is the formula for average deal size?
- Average deal size is total value of the included deals divided by the number of included deals. State which deals are included, because closed-won deals and open opportunities produce different results.
- Can AI calculate average deal size from my CRM?
- Yes, if you export or paste the relevant CRM rows into a tool it can read. It cannot reliably choose the right stages, dates, currencies or duplicate-handling rules without your instructions.
- Can AI calculate average deal size in a sales forecast?
- Yes, it can calculate the historical average used as one input to a forecast. It cannot decide whether that average reflects your future mix of deals, so compare it with current pipeline data and recent changes in deal size.
Nearby answers
Assessed by gpt-5.6-luna (gpt-5.6-luna) on 2026-08-13, second-checked by an independent model. Wrong somewhere? Email [email protected] and it gets re-checked.
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