Compare a Merchant Conversion Quote with a Supplied Issuer-Rate Scenario — Free
A terminal's home-currency quote is not comparable with a local amount until the conversion rate and any separate issuer markup are on the same receipt. Compare the stated scenarios without assuming a future posting rate.
The proof surface
Cash-versus-card budgeting decides payment-method amounts. This receipt compares two conversion routes for the same purchases, using explicit supplied rates and quotes. It does not fetch exchange rates, detect an unlawful fee or guarantee a cheaper route.
InputPurchase code | local-currency amount | home currency per local unit | merchant home-currency quote; additional issuer markup on the supplied benchmark (%)
Rare deviceCash-versus-card budgeting decides payment-method amounts. This receipt compares two conversion routes for the same purchases, using explicit supplied rates and quotes. It does not fetch exchange rates, detect an unlawful fee or guarantee a cheaper route.
Output artifactMerchant quote minus supplied issuer scenarios with row-by-row context
Cost$0 local calculation · no card, paid key, subscription or signup · proposed filing price is not for sale
Sample, not your facts: Illustrative inputs: Bookshop purchase | 47.5 | 1.08 | 56; Cafe purchase | 18 | 1.08 | 20.5. Additional issuer markup on the supplied benchmark (%) = 3. Merchant quote minus supplied issuer scenarios: 3.6378 home-currency units difference. All records are invented.
Before using the currency-choice receipt
Use one local currency and one home currency throughout the run. The rate field is home-currency units per one local unit, not its reciprocal. Obtain the benchmark and a contemporaneous merchant quote from suitable sources; neither is verified by the app. The markup setting is additional to the entered benchmark. If the supplied issuer rate already includes the fee, set the additional markup accordingly rather than charging it twice. The model uses percentage markup only, excluding fixed fees, minimum fees, cash-advance rules and posting-date movement. Rows are separate purchases whose home-currency differences can be added; they are not several quotes for one purchase to be counted as several charges.
Why the flat version breaks
Entering the reciprocal exchange rate
A rate of 1.08 home units per local unit differs from 1.08 local units per home unit. The receipt assumes the first orientation. Keep currency names and orientation in your source notes, and verify them before attributing a difference to conversion markup.
Adding a fee twice
An inclusive quoted rate may already contain the issuer's fee. Applying the markup setting again would overstate the issuer scenario. The input asks for an additional percentage only. Obtain a clear explanation rather than assuming a marketing rate and a fee schedule are independent charges.
Promising the eventual statement price
Posting dates, network rules, fixed charges and rounding can change the actual result. The app has no live-rate feed or account information. Keep the rate timestamp and omitted terms with the comparison; a positive difference is not an automatic refund entitlement or proof of an unlawful merchant practice.
How to work the currency-choice receipt
Get a quote and a correctly oriented benchmark
Record the local amount, displayed home-currency quote and the benchmark rate at a relevant time. Note sources and dates privately. A rate written as local currency per home unit must be inverted before entry; the app cannot identify a reciprocal from a plausible decimal. Anonymous purchase codes avoid sharing merchant and itinerary details unnecessarily.
Separate an additional fee from an inclusive rate
Ask the issuer which percentage is additional and whether the entered benchmark already incorporates conversion costs. Use a zero additional markup when that is the correct source convention. A fixed or minimum fee needs a different reviewed model; do not disguise it as a percentage calculated from this one purchase.
Compute both scenarios with a declared sign
Multiply local amount by home units per local unit, then multiply by one plus markup/100 for the issuer scenario. Subtract that modeled amount from the merchant home-currency quote. Positive means the quote is higher under these inputs; negative means lower. The receipt retains each rate and both totals, not merely a suggested button to press.
Confirm terms before authorizing a purchase
Review the actual terminal choice and issuer terms, including whether a decline of merchant conversion keeps the transaction in local currency. Ask the issuer about any uncertain fee or rate basis. This comparison is scenario arithmetic, not a prediction of the statement, and no checkout, charge or card details are handled by the app.
What the currency-choice receipt separates
Question
Before
Inspect this instead
Entering the reciprocal exchange rate
A rate of 1.08 home units per local unit differs from 1.08 local units per home unit. The receipt assumes the first orientation. Keep currency names and orientation in your source notes, and verify them before attributing a difference to conversion markup.
Separate an additional fee from an inclusive rate
Adding a fee twice
An inclusive quoted rate may already contain the issuer's fee. Applying the markup setting again would overstate the issuer scenario. The input asks for an additional percentage only. Obtain a clear explanation rather than assuming a marketing rate and a fee schedule are independent charges.
Compute both scenarios with a declared sign
Promising the eventual statement price
Posting dates, network rules, fixed charges and rounding can change the actual result. The app has no live-rate feed or account information. Keep the rate timestamp and omitted terms with the comparison; a positive difference is not an automatic refund entitlement or proof of an unlawful merchant practice.
Confirm terms before authorizing a purchase
This currency-choice receipt replaces a manual count or calculation, not source verification or the responsible person’s review.
Run it on the samples, right here
FIRST-LOAD
HYPOTHESIS / PROTOTYPE — checkout unavailable. Calculation is local. A draft is saved automatically in this browser profile when storage is available; Reset to sample clears it. Optional Pro history stores only five summaries and has its own deletion control. State links encode your inputs and can remain in browser history, clipboard or recipients’ records; share only non-sensitive rows. Optional external AI formatting leaves this device. The required site analytics beacon reports page activity; shared URLs contain encoded inputs. Do not treat an encoded URL as private. The calculator has no input-collection endpoint.
Conversion-scenario arithmetic only, not financial or legal advice or a guaranteed statement amount. Confirm the benchmark orientation, additional fees and transaction terms with the card issuer before authorizing a consequential purchase.
Data note: The currency-choice receipt processes Purchase code | local-currency amount | home currency per local unit | merchant home-currency quote locally. Starter/sample selection and Run compute in this tab; no input is sent by the calculator. A local draft may be saved; explicit state-link sharing or optional external AI formatting can disclose inputs. Use non-sensitive labels.
Go deeper: the companion app files the same reading as a till receipt with a tear-off foot
The article demo above runs without limits. The companion app keeps a local history, exports the rows as CSV, prints the currency-choice receipt reading, and holds your drafts on this device — one complete free app run; the proposed $4 one-time filing layer is not for sale.
The currency-choice receipt answer stays complete for free. The proposed $4 one-time filing layer adds row CSV, print and five local reading summaries, not hidden answers. Checkout is unavailable; the article demo remains unlimited.
Conversion-scenario arithmetic only, not financial or legal advice or a guaranteed statement amount. Confirm the benchmark orientation, additional fees and transaction terms with the card issuer before authorizing a consequential purchase.
What this is built on
Method: Multiply local amount by home units per local unit, then multiply by one plus markup/100 for the issuer scenario. Subtract that modeled amount from the merchant home-currency quote. Positive means the quote is higher under these inputs; negative means lower. The receipt retains each rate and both totals, not merely a suggested button to press.
All sample records, dates, quantities and labels are invented. No outside policy, contract, rate, clock offset, measurement or accessibility standard is represented as verified.
Google’s official pricing documentation, fetched 2026-10-01, says AI Studio is free in available regions. Optional formatting may require a Google account; manual local entry requires none. Limits can change and free-tier content may be used to improve products. Do not send private records.
Before: two differently denominated prices were compared by intuition. After: one oriented benchmark and a separate markup make the signed quote difference inspectable.
Setting: Additional issuer markup on the supplied benchmark (%) = 3. Expected summary: 3.6378 home-currency units difference.
Bookshop's benchmark conversion is 47.5×1.08 = 51.3 home units; applying the separate 3% markup gives 52.839. Its merchant quote is 3.161 higher. Cafe's issuer scenario is 18×1.08×1.03 = 20.0232, and its quote is 0.4768 higher. The signed total difference is 3.6378 home units. All rates and quotes are invented, not a live card-network comparison.
Setting: Additional issuer markup on the supplied benchmark (%) = 3. Expected summary: -1.784 home-currency units difference.
Ticket's issuer scenario is 74.16 home units, so the 72 merchant quote is 2.16 lower under these inputs. Taxi's issuer scenario is 11.124, making its 11.5 quote 0.376 higher. The total is -1.784. A negative modeled difference does not overturn the need to verify fees or posting rates; it simply shows that the declared assumptions, not a blanket rule, drive this comparison.
Sample C — boundary convention
Map purchase | 10 | 1 | 10.3
Setting: Additional issuer markup on the supplied benchmark (%) = 3. Expected summary: 0 home-currency units difference.
Ten local units at a one-for-one supplied benchmark and a separate 3% markup produce 10.3 home units, equal to the quote. The modeled difference is zero. Rounding, posting dates, minimum fees and merchant terms are not included, so equality here does not certify that the final statement charges would be identical.
Optional AI formatting, never the calculation
Manual entry completes this currency-choice receipt for free without signup. If available to you, the free AI Studio interface linked in the sources may format fictional or non-sensitive notes; external access may require an account. No API key or AI call is built into this tool. Free-tier content may be used to improve products. Review each cell and transcribe it to the labeled row schema; do not paste the JSON object into the row box.
Format only these fictional or non-sensitive notes for a currency-choice receipt. Return strict JSON shaped as {"rows": [{"label": "string", "cells": ["string", "string", "string"]}], "setting": "string"}. The columns are Purchase code | local-currency amount | home currency per local unit | merchant home-currency quote; the setting is Additional issuer markup on the supplied benchmark (%). Keep all supplied strings and quantities exactly; do not calculate, infer missing entries, invent dates or add advice. If any required value is missing, return an empty rows array and ask me for it separately. I will verify every cell against my source and manually transcribe rows using vertical bars before running the local calculator.
An AI response is not executed, fetched or trusted as a result. Missing values remain questions; the strict local parser checks the rows you actually enter.