The Exchange Rate History Calculator allows you to track how the value of one currency has changed in relation to another over a specified period. This is crucial for various financial activities, including international trade, investment, travel planning, and economic analysis.
How it works: You input the two currencies you want to compare (e.g., US Dollar to Euro) and a date range. The calculator then retrieves historical exchange rate data for that period and presents key metrics such as the highest rate, lowest rate, average rate, and the percentage change between the start and end dates.
Why it's important:
Investment Decisions: Investors use historical data to identify trends and forecast future currency movements, informing their decisions on foreign investments.
International Business: Businesses engaged in import/export activities need to understand currency fluctuations to manage risks, set prices, and ensure profitability.
Personal Finance: Individuals planning international travel or remittances can use historical rates to budget effectively and find opportune times to exchange money.
Economic Analysis: Economists and policymakers monitor currency histories to assess economic health, understand inflation, and predict trade balances.
By using this calculator, you gain valuable insights into currency volatility and historical performance, empowering you to make more informed financial choices.
function calculateExchangeRateHistory() {
var baseCurrency = document.getElementById("baseCurrency").value.toUpperCase();
var targetCurrency = document.getElementById("targetCurrency").value.toUpperCase();
var startDate = document.getElementById("startDate").value;
var endDate = document.getElementById("endDate").value;
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = ""; // Clear previous results
if (!baseCurrency || !targetCurrency || !startDate || !endDate) {
resultDiv.innerHTML = "Please fill in all fields.";
return;
}
if (startDate > endDate) {
resultDiv.innerHTML = "Start date cannot be after end date.";
return;
}
// — IMPORTANT: Replace this placeholder with actual API call or data retrieval —
// In a real-world scenario, you would call an API (like Alpha Vantage, Fixer.io, etc.)
// to get historical exchange rate data for the specified currencies and dates.
// For demonstration, we'll use dummy data.
var dummyHistoricalRates = getDummyHistoricalRates(baseCurrency, targetCurrency, startDate, endDate);
if (!dummyHistoricalRates || dummyHistoricalRates.length === 0) {
resultDiv.innerHTML = "Could not retrieve historical data for the specified currencies and dates. Please check your inputs or try again later.";
return;
}
var rates = [];
var dates = [];
var sum = 0;
var minRate = Infinity;
var maxRate = -Infinity;
for (var i = 0; i < dummyHistoricalRates.length; i++) {
var entry = dummyHistoricalRates[i];
var rate = entry.rate; // Assuming the dummy data has a 'rate' property
if (typeof rate !== 'number' || isNaN(rate)) {
console.warn("Skipping invalid rate data:", entry);
continue;
}
rates.push(rate);
dates.push(entry.date); // Assuming dummy data has a 'date' property
sum += rate;
if (rate maxRate) maxRate = rate;
}
if (rates.length === 0) {
resultDiv.innerHTML = "No valid rate data found for the specified period.";
return;
}
var averageRate = sum / rates.length;
var startRate = rates[0];
var endRate = rates[rates.length – 1];
var percentageChange = ((endRate – startRate) / startRate) * 100;
var output = `
Exchange Rate History (${baseCurrency}/${targetCurrency})
Period: ${startDate} to ${endDate}
Average Rate: ${averageRate.toFixed(4)} ${targetCurrency}/${baseCurrency}
Lowest Rate: ${minRate.toFixed(4)} ${targetCurrency}/${baseCurrency}
Highest Rate: ${maxRate.toFixed(4)} ${targetCurrency}/${baseCurrency}
Rate on ${startDate}: ${startRate.toFixed(4)} ${targetCurrency}/${baseCurrency}
Rate on ${endDate}: ${endRate.toFixed(4)} ${targetCurrency}/${baseCurrency}
Percentage Change: ${percentageChange.toFixed(2)}%
`;
resultDiv.innerHTML = output;
}
// — Dummy Data Function (REPLACE WITH REAL API CALL) —
function getDummyHistoricalRates(base, target, start, end) {
// This is a placeholder. In a real application, you would fetch this data from an API.
// The structure of the returned data should be an array of objects, e.g.:
// [{ date: "YYYY-MM-DD", rate: 1.2345 }, …]
var availableCurrencies = ["USD", "EUR", "GBP", "JPY", "CAD", "AUD"];
if (!availableCurrencies.includes(base) || !availableCurrencies.includes(target)) {
console.error("Dummy data only supports: USD, EUR, GBP, JPY, CAD, AUD");
return [];
}
var data = [];
var currentDate = new Date(start);
var endDate = new Date(end);
var rateOffset = Math.random() * 0.5 – 0.25; // Simulate some fluctuation
var baseRate = 1.0;
if ((base === "USD" && target === "EUR") || (base === "EUR" && target === "USD")) baseRate = 0.92;
else if ((base === "USD" && target === "GBP") || (base === "GBP" && target === "USD")) baseRate = 0.79;
else if ((base === "USD" && target === "JPY") || (base === "JPY" && target === "USD")) baseRate = 150.5;
else if ((base === "USD" && target === "CAD") || (base === "CAD" && target === "USD")) baseRate = 1.35;
else if ((base === "USD" && target === "AUD") || (base === "AUD" && target === "USD")) baseRate = 1.52;
// Add more base rates for other pairs as needed for dummy data
if (base !== "USD") baseRate = 1 / baseRate; // Adjust if not USD as base
while (currentDate <= endDate) {
var dateString = currentDate.toISOString().split('T')[0];
var dailyFluctuation = Math.random() * 0.02 – 0.01; // Small random daily change
var currentRate = baseRate * (1 + rateOffset + dailyFluctuation);
if (currentRate target
});
currentDate.setDate(currentDate.getDate() + 1);
}
return data;
}