As of 13 August 2026, AI can only partly calculate your paid-ad budget.

What to actually do

1. Hand it to a person

   The route this page recommends

   A person who owns the outcome does this end to end, worth it when the failure is dear.

2. Use a tool built for this

   Second choice

3. Do it yourself

   The distant third

   A chat interface, chat-fluent skill, and roughly 30 minutes until you can act on the result.

   How to actually do it

   1. Open your latest Google Ads, Meta Ads or other paid-media reports and record spend, clicks, leads, sales, cost per click, cost per lead and conversion rates for a comparable period.
   2. Gather your current price, gross margin or contribution per sale, average order value, repeat-purchase information and the maximum amount you can afford to pay for a sale or lead.
   3. Write down the business target, campaign period, available sales capacity, existing marketing budget and any minimum or maximum spend limit.
   4. Paste the supplied prompt into a chatbot, replace every bracketed slot with your figures, and attach or paste the relevant report totals without including customer-identifying data.
   5. Check each table calculation with a spreadsheet by multiplying the proposed clicks or leads by the relevant cost and conversion assumptions, then compare the assumptions with your current platform reports.
   6. Choose a test budget only after checking that the expected contribution covers the proposed spend under the cautious scenario, and set a review point based on a fixed amount of spend or a defined number of conversions.
   7. Ask a colleague or qualified marketing consultant to challenge the assumptions before you publish the budget if the amount is material to the business.

   Prompt

   Help me calculate a paid-ad budget for [business or product] in the UK. Do not invent any figures. Use only the information I provide, label every assumption, and show the arithmetic in a table.
   
   My objective is: [sales, leads, bookings or other outcome]
   My target outcome for the period is: [number]
   The period is: [weeks or months]
   Average revenue per sale or customer: £[amount]
   Gross margin or contribution per sale: [percentage or £ amount]
   Maximum acceptable cost per sale or lead: £[amount]
   Current conversion rate from ad click to [sale or lead]: [percentage]
   Current cost per click or cost per lead, if known: £[amount]
   Current conversion rate from lead to sale, if relevant: [percentage]
   Expected repeat purchases or customer lifetime value, if known: £[amount]
   Available sales or fulfilment capacity during the period: [details]
   Existing marketing budget: £[amount]
   Any minimum or maximum budget constraint: [details]
   
   Calculate three scenarios: cautious, base case and ambitious. For each, show the required number of clicks or leads, estimated media spend, expected outcomes, break-even point and the figures that drive the result. If a required input is missing, stop and list it rather than guessing. Separate arithmetic from judgement. Explain which result is safest to test first, what measurement setup is needed, and what evidence would justify increasing or reducing the budget. State clearly that this is not professional advice and that I remain responsible for the spend.

   Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.