# Currency converter and transfer fee calculator documentation

Inputs, formulas, assumptions and API/MCP examples for the currency converter and transfer fee calculator. Reproduce a calculation and cite its sources.

Canonical calculator: https://klarfort.com/tools/currency-converter/
Content updated: 2026-09-07
Assumptions reviewed: 2026-09-07

## Overview
Estimate the amount a recipient receives after an entered exchange rate and transfer fee. Compare that quote with a reference rate to see the combined effect of the rate difference and fee.

Both rates use target-currency units per one source-currency unit. For example, a USD to AED rate of 3.6725 means 3.6725 dirhams for one US dollar. Reference rates are indicative.

## How to use
1. Choose the currency you pay and the currency the recipient receives, then enter the transfer amount.
2. Enter the reference rate and the actual rate quoted for the same currency direction.
3. Enter the fee in the source currency and select whether it is deducted from the amount or paid on top.
4. Calculate to compare the amount received, total source cost, effective rate and cost relative to the reference.

## Understanding the result
The amount received uses the quoted rate after any deducted fee. The effective rate divides what arrives by your total cost, including an added fee.

Transfer cost compares your total source-currency outlay with the reference value of what arrives. A negative cost means the entered quote beats that reference after fees; it does not confirm that a transaction is available.

## Questions
### What is the difference between the quoted and effective exchange rates?
The quoted rate applies to the money being converted. The effective rate also accounts for the entered fee, expressing the amount received per unit of total source-currency cost.

### Is a transfer fee deducted or added?
Choose deducted if the fee comes out of the transfer amount before conversion. Choose added if you pay it separately on top. In both cases, enter the fee in the currency you send.

### Does the calculator compare providers or guarantee a rate?
No. It compares the reference, quote and fee you enter. It does not use provider fee tables, execute transfers or include charges that are missing from your inputs.

### What does the KlarFort snapshot time mean for exchange rates?
It shows when KlarFort retrieved its reference-rate snapshot, not when an underlying exchange rate was observed. The reference uses ECB rates, with AED derived from its USD peg. Loading it fills the reference rate only; your quoted rate and fee remain yours to enter. If a reference is unavailable, manual entry still works.

## Default worked example
Amount received: 3,631.75 AED. Estimated AED received after your quoted rate and fee. Assumptions as of 2026-09-07.

## Formula
Received = (amount − deducted fee) × quoted rate. Effective rate = received ÷ total source cost. Cost = total cost − received ÷ reference rate.

- Rates are target units per one source unit and are indicative, not executable transaction quotes.
- All fees are entered by you in the source currency. No provider fee tables or guarantees are used.

## Inputs
- fromCurrency: From currency; default "USD"
- toCurrency: To currency; default "AED"
- amount: Transfer amount; default 1000
- midMarketRate: Target currency units per one source currency unit; indicative only.; default 3.6725
- quotedRate: Target currency units per one source currency unit.; default 3.65
- fee: Transfer fee in source currency; default 5
- feeMode: Deducted: fee comes out of the entered amount. Added: fee is paid on top.; default "deducted"

## Interfaces
Input schema: https://klarfort.com/tools/currency-converter/schema.json
Worked request and response: https://klarfort.com/tools/currency-converter/examples.json
Public table: https://klarfort.com/tools/currency-converter/table.json
JSON API: POST https://klarfort.com/tools/api/v1/currency-converter
MCP endpoint: POST https://klarfort.com/tools/mcp
MCP tool name: currency-converter

## JSON request body
```json
{
  "fromCurrency": "USD",
  "toCurrency": "AED",
  "amount": 1000,
  "midMarketRate": 3.6725,
  "quotedRate": 3.65,
  "fee": 5,
  "feeMode": "deducted"
}
```

## Usage and credit
Free for personal, commercial and any other lawful use with credit to KlarFort at https://klarfort.com/. Third-party data terms still apply.

Computed with KlarFort Calculators, https://klarfort.com/

Place a visible credit near the reused material or in the credits for your work or integration. One clear credit per work or integration is sufficient; no separate credit per API request is required. The credit_url field contains the homepage. The citation_url field is an optional calculator reference. Full permission: https://klarfort.com/tools/docs/license/

## Sources
KlarFort calculation methodology: https://klarfort.com/tools/methodology/ (1)