As of 13 August 2026, AI can work out your cost-plus price.

What to actually do

1. Use a tool built for this

   The route this page recommends

2. Do it yourself

   Second choice

   A chat interface, no skill needed, and roughly 30 minutes until you can act on the result.

   How to actually do it

   1. Open your latest accounts, management figures or cost spreadsheet and gather the direct cost per unit, regular overheads, one-off costs, expected sales volume, channel fees, delivery costs and payment fees.
   2. Decide whether your target percentage is a markup on cost or a margin on the selling price, then write that choice beside the percentage.
   3. Paste the prompt into a chatbot and replace every bracketed slot with your figures, units, periods and VAT information; write "unknown" where you do not have a reliable figure.
   4. Answer the chatbot's questions using your accounts, supplier invoices, contracts and sales records rather than allowing it to fill gaps.
   5. Copy the resulting calculation into a spreadsheet and recalculate the cost per sale, markup or margin, VAT treatment and customer price from the displayed formula.
   6. Compare each input and scenario against your current cost records and price list, then change the assumptions for realistic volume, discounts and channel fees.
   7. Send the checked scenarios to the person who approves pricing in your business, and record the chosen assumptions and review date before publishing the price.

   Prompt

   Work out a cost-plus price for my product or service using only the information I provide. Do not invent, estimate or fill in missing figures. First list the inputs you need, including unit cost, allocated overhead, one-off costs, expected sales volume, target markup or target margin, sales channel fees, delivery or packaging costs, discounts, and whether VAT applies. Then calculate the cost per sale and show the formula step by step. Keep markup and margin separate and label which one I supplied. Produce a table with the recommended price, the assumptions, and at least three clearly labelled scenarios using only figures I provide. If any input is missing or ambiguous, ask me a question instead of calculating it. Show the price before VAT and, only if I provide the relevant VAT treatment, the customer price including VAT. Flag any costs that may have been omitted and explain how the result changes if each supplied assumption changes. Do not tell me that the price is commercially correct. End with a checklist of figures and assumptions I must verify against my accounts, supplier invoices and current price list.
   
   Product or service: [description]
   Currency: GBP
   Unit or delivery cost: [figure and what it covers]
   Allocated overhead per unit or period: [figure and allocation method]
   One-off costs to recover: [figure and recovery period or volume]
   Expected sales volume: [quantity and period]
   Target markup or margin: [percentage and whether markup or margin]
   Sales channel fees: [figure or percentage]
   Delivery, packaging and payment costs: [figures]
   Discounts or promotions: [details]
   VAT treatment: [details, or say unknown]
   Other relevant costs or constraints: [details]

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

3. Hand it to a person

   The distant third

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