Currency exchange amount calculator
Enter the rate you were quoted, such as 0.92 euros per dollar, then add a markup on the rate and a fee on the result: you see the effective rate, the fee and the net amount you receive. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Amount
- 1,000
- Interest rate
- 0.92
- From currency
- USD
- To currency
- EUR
- Fee percent
- 0
- Markup percent
- 0
- Effective rate
- 0.92
- Gross converted
- 920
Travelers, freelancers, and finance tools often need a transparent currency conversion that does not hide bank markup or card fees inside a live quote. This currency exchange amount calculator takes the amount you hold, the exchange rate you supply (mid-market, airport board, invoice quote, or corporate desk), and optionally a markup percentage on that rate plus a conversion fee percentage on the gross result. It returns the effective rate, gross converted amount, fee amount, and net amount you actually receive—or the true all-in cost of buying foreign cash—without calling any network FX feed.
How the conversion formula works with markup and fee
Currency conversion at a known rate is multiplication, but real travel and business quotes almost always layer a spread and sometimes a separate commission. This calculator models that stack explicitly. Start with amount in the source currency and rate as target units per one source unit—for example rate 0.92 means one US dollar buys 0.92 euros on the quote you trust.
Setting both percentages to zero recovers a clean mid-market multiply. Setting only markup models a spread-only desk; setting only fee models a flat percentage commission on the converted side. Because markup is applied first, a two percent markup and a one and a half percent fee compound in a predictable order you can document next to a receipt.
Precision defaults to two decimal places, which matches common cash rounding, and can be raised to fifteen for internal accounting goldens.
Where a user-rate FX calculator earns its keep
Trip planners compare an airport board rate against a bank card’s effective cost by entering the board rate plus the card’s typical markup and fee percentages side by side. Freelancers converting an invoice total into home currency for tax notes use the rate printed on the payment processor statement so the net matches the deposit. Because the capability never claims a live mid-market quote, it stays honest for SEO and for compliance: you always disclose that the user supplied the rate.
Keep requests small, pin rounded outputs in tests, and you get reproducible conversion math for apps, LMS demos, and edge workers without foreign-exchange vendor contracts.
What you can do with it
Invoice and remittance netting
Convert a foreign invoice at the rate on the payment receipt, apply the processor fee percent, and store gross, fee, and net for bookkeeping.
Trip budget worksheets
Multiply daily spend plans into local currency with a conservative markup so travelers do not under-budget when the desk rate is worse than the headline.
FAQ
How do I convert an amount between two currencies?
Send amount (source) and rate (target units per one source unit).
Does this use live exchange rates?
No. You supply the rate. The calculator never fetches market data; it only applies your rate, optional markup, and optional fee with deterministic arithmetic.
In what order are the markup and the fee applied?
The markup comes first and changes the rate; the fee is then taken as a percentage of the converted amount, not of your original cash. So a 2% markup and a 1.5% fee always combine in the same order, easy to note next to a receipt.
How do I compare an airport rate with my bank card?
Run the calculation twice: once with the rate on the airport board, and once with that rate plus your card's usual markup and fee percentages. The two net amounts side by side show which option leaves you with more.
What happens if I leave both percentages at zero?
You get a plain multiplication of the amount by the rate, as with a mid-market quote. Set only the markup to model a desk that earns on the spread, or only the fee to model a flat commission on the converted side.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/travel/currency-exchange \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"amount":1000,"rate":0.92}'const res = await fetch("https://api.kit.forhosting.com/travel/currency-exchange", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"amount": 1000,
"rate": 0.92
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/travel/currency-exchange",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"amount": 1000,
"rate": 0.92
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/travel/currency-exchange", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"amount":1000,"rate":0.92}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"amount":1000,"rate":0.92}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/travel/currency-exchange", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"amount": 1000,
"rate": 0.92
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "travel.currency_exchange",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Failed validation is not billed; successful calls use the published $0.002 base price per item.
How the conversion formula works with markup and fee
An optional markup_percent widens the rate the way a bureau or card issuer might: effective_rate equals rate times one plus markup_percent over one hundred. The gross converted amount is then amount times effective_rate. An optional fee_percent is applied to that gross figure, not to the original cash: fee_amount equals gross times fee_percent over one hundred, and net_converted equals gross minus fee. Amounts and rates must be finite; amount must be non-negative; rate must be strictly greater than zero; fee_percent must sit between zero and one hundred inclusive; markup_percent must be non-negative. Optional from_currency and to_currency labels are echoed for display only—they never fetch a live price.
Input contract, response fields, and error behaviour
Optional precision is an integer from zero to fifteen. Currency labels appear only when you supplied them, so optional fields are omitted rather than set to null. POST a JSON body with amount and rate as required finite numbers. You may send them as JSON numbers or as plain decimal strings; empty strings, Infinity, and NaN fail with invalid_input naming the field. Optional fee_percent defaults to zero when omitted; optional markup_percent likewise. Optional from_currency and to_currency are free-form labels up to thirty-two characters—use ISO 4217 codes such as USD and EUR if you want consistency in reports, but the solver does not validate against a currency registry. On success the body echoes amount, rate, fee_percent, and markup_percent (rounded), plus effective_rate, gross_converted, fee_amount, net_converted, precision, a stable formula string, and method user_rate_markup_fee. Example: amount one thousand, rate zero point nine two, markup two, fee one point five yields effective_rate zero point nine three eight four, gross nine hundred thirty-eight point four zero, fee about fourteen point zero eight, and net about nine hundred twenty-four point three two at two-decimal precision. Negative amount, non-positive rate, fee outside zero to one hundred, or negative markup produce invalid_input and are not billed.
Where a user-rate FX calculator earns its keep
Corporate travel desks batch dozens of per-diem lines through the API at $0.002 per successful call without standing up a paid market-data subscription when the rate is already known. Educational posts about “how much fee am I really paying” can fix amount and rate and sweep fee_percent to show the net curve without inventing market ticks.
Integration use cases
Compare bureau vs card true cost
Enter the same amount and mid-market rate twice: once with airport markup and fee, once with card markup, and compare net_converted before you withdraw cash abroad.
Technical questions
What is the difference between markup_percent and fee_percent?
Markup widens the rate first: effective_rate = rate × (1 + markup/100). Fee is then taken from the gross converted amount: fee = gross × fee/100; net = gross − fee.
What inputs are rejected?
Negative amount, rate not greater than zero, fee_percent outside 0–100, negative markup_percent, non-finite numbers, or missing required fields fail with invalid_input and are not billed.
What does the currency exchange amount calculator cost?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.