.currency-calc-container {
max-width: 600px;
margin: 20px auto;
padding: 25px;
background-color: #f8f9fa;
border: 1px solid #e9ecef;
border-radius: 8px;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.currency-calc-title {
text-align: center;
color: #2c3e50;
margin-bottom: 25px;
font-size: 24px;
font-weight: 700;
}
.calc-row {
margin-bottom: 15px;
display: flex;
flex-wrap: wrap;
gap: 15px;
}
.calc-group {
flex: 1;
min-width: 200px;
}
.calc-label {
display: block;
margin-bottom: 5px;
font-weight: 600;
color: #495057;
font-size: 14px;
}
.calc-input {
width: 100%;
padding: 10px;
border: 1px solid #ced4da;
border-radius: 4px;
font-size: 16px;
box-sizing: border-box;
}
.calc-input:focus {
border-color: #80bdff;
outline: none;
box-shadow: 0 0 0 0.2rem rgba(0,123,255,.25);
}
.calc-btn {
width: 100%;
padding: 12px;
background-color: #007bff;
color: white;
border: none;
border-radius: 4px;
font-size: 16px;
font-weight: 600;
cursor: pointer;
transition: background-color 0.2s;
margin-top: 10px;
}
.calc-btn:hover {
background-color: #0056b3;
}
.calc-results {
margin-top: 25px;
background-color: #fff;
padding: 20px;
border-radius: 4px;
border: 1px solid #dee2e6;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
padding: 10px 0;
border-bottom: 1px solid #eee;
}
.result-row:last-child {
border-bottom: none;
}
.result-label {
color: #6c757d;
}
.result-value {
font-weight: 700;
color: #212529;
}
.result-value.highlight {
color: #28a745;
font-size: 1.1em;
}
.article-container {
max-width: 800px;
margin: 40px auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
}
.article-container h2 {
color: #2c3e50;
margin-top: 30px;
}
.article-container h3 {
color: #34495e;
margin-top: 20px;
}
.article-container ul {
margin-bottom: 20px;
}
.formula-box {
background-color: #eef2f7;
padding: 15px;
border-left: 4px solid #007bff;
margin: 15px 0;
font-family: monospace;
}
function calculateCurrency() {
// Get input values
var amount = parseFloat(document.getElementById("sourceAmount").value);
var rate = parseFloat(document.getElementById("exchangeRate").value);
var feePct = parseFloat(document.getElementById("feePercent").value);
var fixedFee = parseFloat(document.getElementById("fixedFee").value);
// Validation
if (isNaN(amount) || amount <= 0) {
alert("Please enter a valid amount to exchange.");
return;
}
if (isNaN(rate) || rate <= 0) {
alert("Please enter a valid exchange rate.");
return;
}
if (isNaN(feePct)) feePct = 0;
if (isNaN(fixedFee)) fixedFee = 0;
// Logic
// 1. Calculate percentage fee amount based on the source amount
var percentFeeAmount = amount * (feePct / 100);
// 2. Total fees in source currency
var totalFees = percentFeeAmount + fixedFee;
// 3. Net amount remaining to be converted
var netAmount = amount – totalFees;
// Handle case where fees exceed amount
if (netAmount < 0) {
alert("Fees exceed the total amount to exchange. Please adjust inputs.");
return;
}
// 4. Final converted amount
var finalAmount = netAmount * rate;
// 5. Effective Exchange Rate (Actual value realized per 1 unit of source currency)
// Formula: Final Amount Received / Original Source Amount
var effectiveRate = finalAmount / amount;
// 6. Reciprocal Rate (Inverse)
var reciprocal = 1 / rate;
// Display Results
document.getElementById("resultsArea").style.display = "block";
document.getElementById("displayFees").innerHTML = totalFees.toFixed(2);
document.getElementById("displayNetAmount").innerHTML = netAmount.toFixed(2);
document.getElementById("displayFinalAmount").innerHTML = finalAmount.toFixed(2);
document.getElementById("displayEffectiveRate").innerHTML = effectiveRate.toFixed(4);
document.getElementById("displayReciprocal").innerHTML = reciprocal.toFixed(4);
}
How to Calculate Currency Exchange Rates
Understanding how to calculate currency exchange rates is essential for international travel, business transactions, and forex trading. The exchange rate tells you the value of one currency relative to another. While the basic calculation is multiplication, determining the effective rate often requires accounting for hidden fees and commissions.
The Basic Exchange Rate Formula
To convert a specific amount of money from your home currency (Source) to a foreign currency (Target), you use the following multiplication formula:
Target Amount = Source Amount × Exchange Rate
For example, if you want to convert 500 units of currency A to currency B, and the rate is 1.20:
- Source Amount: 500
- Rate: 1.20
- Calculation: 500 × 1.20 = 600
You would receive 600 units of currency B.
Calculating the Inverse (Reciprocal) Rate
Sometimes you see a rate quoted in the opposite direction than what you need. If you know that 1 USD = 0.85 EUR, but you want to know how many USD you get for 1 EUR, you calculate the reciprocal:
Inverse Rate = 1 ÷ Original Rate
Using the example above: 1 ÷ 0.85 ≈ 1.176. Therefore, 1 EUR is worth approximately 1.176 USD.
How to Calculate the "Real" Exchange Rate
Banks and exchange services rarely trade at the "mid-market" rate (the one you see on Google). They make money by adding a margin to the rate (the "spread") or by charging explicit fees. To calculate the Effective Exchange Rate—the true cost of your transfer—you must factor in these costs.
Step 1: Determine Total Fees. Add up any fixed service charges and percentage-based commissions. Deduct this from your sending amount.
Step 2: Convert the Net Amount. Multiply the remaining money by the quoted exchange rate.
Step 3: Divide by Original Amount. Divide the final amount of foreign currency received by the original amount you started with.
Effective Rate = Final Amount Received ÷ Original Source Amount
If the effective rate is significantly lower than the market rate, you are paying a high premium for the currency exchange. Using the calculator above allows you to input these fees to see exactly how much value you are retaining during the transaction.
Cross Rates
If you need to find the exchange rate between two currencies (Currency A and Currency C) but only have the rates against a common third currency (Currency B, usually USD), you calculate the cross rate:
- Rate A/B = 1.5 (A to USD)
- Rate C/B = 0.75 (C to USD)
- Cross Rate A/C: 1.5 ÷ 0.75 = 2.0
This means 1 Unit of Currency A buys 2 Units of Currency C.