Market inventory calculator
How much should I bring to market, from what sold before or from the shoppers I expect?
Showing for United States
Bring next time
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- Sell-through
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- Sold per market, on average
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- Left over per market, on average
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- Left over per market, at cost
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Use it for one product at a time, such as dozens of eggs or bunches of carrots.
If you sold out, you sold all you brought, and more might have sold. Add a buffer for that market.
The buffer is extra stock in case the day goes better. It is not in the takings you expect.
Bring
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- Buyers you expect
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- Units you expect to sell
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- Takings you expect
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Use it for one product at a time, such as dozens of eggs or bunches of carrots.
For a market you have not done, the shoppers and the share who buy are your best guesses. The market manager and other vendors can tell you how busy it gets.
The buffer is extra stock in case the day goes better. It is not in the takings you expect.
Enter your numbers to see the result.
Planning a farm stand, a CSA or a shop? TallyTill is free to start.
Get started with TallyTill for freeUse this calculator in an AI chat
You can ask Claude, ChatGPT or another AI app to work this out for you, and this calculator opens right inside the chat. You connect TallyTill to your AI app once. It is free, and there is no account and no sign-in.
AI apps call add-ons like this connectors, apps or MCP servers. They all mean the same thing: a way for the AI to use a tool someone else made.
1. Copy this address
2. Add it to your AI app
Claude (claude.ai and the Claude desktop app)
- Open Customize, then Connectors.
- Press + Add, then Add custom connector.
- Name it TallyTill calculators, paste the address and press Continue.
- Under Authentication choose No sign in, then press Add.
- In a new chat, press + at the bottom left, choose Connectors and switch TallyTill calculators on.
On Claude's free plan you can add one custom connector.
ChatGPT
- In Settings, turn on Developer mode. OpenAI moves this switch from time to time; it is usually with the settings for apps and connectors.
- Add a new connector (ChatGPT may call it an app), paste the address and choose No authentication.
- In a new chat, choose TallyTill from the tools menu, or type @ and pick it.
Not every ChatGPT plan lets you add your own connector. If you cannot find the option, your plan may not include it.
Using another AI app? Look in its settings for MCP, add the address as a remote server, and choose no sign-in.
3. Ask your question
Say "use TallyTill", so the AI uses the calculator instead of doing the sum itself. For example:
"Use TallyTill: How much should I bring to market, from what sold before or from the shoppers I expect?"
What you will see
- The calculator opens in the chat with the numbers you gave already filled in. Change any number and the answer updates.
- If a number is missing, the box is highlighted, or the AI asks you for it in plain words.
- The answer links back to this page, so you can check the working.
- The first time, your AI app asks if it may use TallyTill. Choose Allow.
The calculators take numbers only. They never ask for your name, your email or a password.
How this is worked out
Sell-through is what you sold divided by what you brought, across the markets you enter. To plan the next market, the average sold per market is increased by your buffer and rounded up to a whole unit. For a market you have not done, the units you expect to sell are the shoppers times the share who buy from you times the units each buyer takes, times this product's share of what they take. The buffer is added and the result is rounded up to a whole unit.
A worked example
Example numbers only; use your own. Over three markets you brought 60, 60 and 50 and sold 48, 55 and 50. That is a sell-through of 90.00 percent and 51 sold on average. With a 15 percent buffer, bring 59. At 2.00 a unit, the 5.67 left over on average is 11.33 of stock. For a market you have not done, 800 shoppers, 5 percent of whom buy, taking 2 each, with this product half of what they take, is 40 units; with a 20 percent buffer, bring 48.
Nothing you type here is saved.