Card fee calculator
What does taking a card cost me on this sale?
Showing for United States
Card fee
—
- You keep
- —
- Effective rate
- —
- Flat fee's share of the fee
- —
Your processor may round differently.
Price to charge
—
- Card fee
- —
- You keep
- —
Raising the shelf price is a price change, not a card surcharge. Whether you may add a surcharge depends on your card network and where you trade.
Rounding this price up further can, now and then, keep a little less.
Fees if every item is its own sale
—
- Fee if the basket is one sale
- —
- Saving from one fee per basket (negative: the basket costs more)
- —
Your processor may round differently.
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: What does taking a card cost me on this sale?"
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
The fee on a sale is your percentage of the sale, rounded to the currency's smallest unit, plus your flat fee for each charge: round(sale × percent ÷ 100) + flat fee. A second fee, such as an app or platform fee, is worked out the same way on its own and added, because each company rounds its own fee. What you keep is the sale minus the fee, and the effective rate is the fee as a share of the sale. To keep a target, the calculator finds the lowest price, in whole smallest units of the currency, whose net after the rounded fees is at least the target. It checks the prices inside a small window instead of rounding a formula, because the fee is rounded too. For a basket, one fee on the whole basket is compared with the same fee on every item: the flat fee is paid once instead of once per item.
A worked example
Example numbers only; use your own rate. Say a sale is 4.00 and your rate is 2.9 percent plus a flat fee of 0.30. The percentage part is 4.00 × 2.9 percent = 0.116, rounded to 0.12, so the fee is 0.12 + 0.30 = 0.42 and you keep 3.58. That is 10.50 percent of the sale, and 71.43 percent of the fee is the flat part. On a 40.00 sale the same rate costs 1.46, or 3.65 percent. To keep 4.00, the lowest price is 4.43: its fee is 0.13 + 0.30 = 0.43, which leaves 4.00. With three items at 2.00 each, a fee on every item costs 3 × 0.36 = 1.08, and one fee on the 6.00 basket costs 0.47, which saves 0.61.
Nothing you type here is saved.