How to Automatically Update Exchange Rates in Excel with On-Demand Control

For those working with international finance, regularly updating currency exchange rates in Excel spreadsheets is a common task. Manually inputting these rates can be time-consuming and prone to errors. Fortunately, Excel offers ways to link your spreadsheet to external data sources like Oanda.com, allowing you to automatically update exchange rates with a click of a button. This article dives deep into the process, providing a comprehensive guide to efficiently manage currency conversions in your Excel workflows.

The Challenge: Automating Exchange Rate Updates

Many professionals, like the user from the r/excel forum, face the challenge of regularly updating exchange rates in their spreadsheets. They need a way to:

Fetch the latest exchange rates from a reliable source.
Update these rates in their Excel spreadsheet automatically.
Control when the rates are updated to avoid disrupting calculations based on historical data.

Solutions: Linking Excel to Oanda for Exchange Rates

While directly linking to Oanda.com via a built-in Excel feature might be limited, you can employ a couple of effective methods to achieve the desired outcome:

1. Using Excel's "Get Data" Feature (Power Query):

Excel's "Get Data" feature, powered by Power Query, is the most robust and flexible approach. This feature allows you to import data from various sources, including web pages. Here's how you can use it:

Find an Oanda API or Data Feed: Start by researching if Oanda provides an official API or a publicly accessible data feed (e.g., a CSV file) containing the exchange rates you need. This is the most reliable method, but it might require an Oanda account.
Web Scraping (Alternative): If an official API isn't available, you can attempt to web scrape the exchange rates from Oanda's website. Be aware that website structures can change, breaking your query.
Open Power Query: In Excel, go to the "Data" tab and click "Get Data" > "From Web".
Enter the URL: Enter the URL of the API endpoint, data feed, or the web page you're scraping.
Transform the Data: Use Power Query's interface to navigate the data, select the relevant exchange rates, and transform them into a table format.
Load to Worksheet: Load the transformed data to your Excel worksheet.
Set Refresh Control: In the "Data" tab, click "Properties" on the loaded data connection. You can then:
- Disable automatic refresh.
- Enable refresh on-demand by clicking "Refresh All" in the "Data" tab whenever you need the latest rates.
- Use VBA to trigger the refresh with a button click.

2. VBA Scripting (More Advanced):

For users comfortable with VBA (Visual Basic for Applications), you can write a script to fetch data from Oanda and update your spreadsheet. This provides even greater control over the process.

Use the MSXML2.XMLHTTP Object: VBA can use this object to make HTTP requests to Oanda's API (if available) or to scrape the website.
Parse the Data: Depending on the data format (XML, JSON, HTML), you'll need to parse the response to extract the exchange rates.
Update the Spreadsheet: Write the extracted rates to the appropriate cells in your Excel spreadsheet.
Create a Button: Insert a button on your worksheet and assign the VBA script to it. Clicking the button will then execute the code, updating the exchange rates on demand.

Important Considerations:

Oanda's Terms of Service: Before web scraping, make sure to review Oanda's terms of service to ensure you are allowed to scrape their data.
Error Handling: Implement error handling in your VBA code or Power Query to gracefully handle situations where the data source is unavailable or the data format changes.
Data Accuracy: Always verify the accuracy of the fetched exchange rates. While automated methods greatly reduce manual input errors, it's crucial to have a system for regular validation. You may also want to consider gathering data from multiple sources to ensure accuracy.

Example VBA Code Snippet (Illustrative):

Sub GetExchangeRate()

    Dim XML As Object
    Dim URL As String
    Dim Rate As Double

    ' Replace with the actual Oanda API endpoint or web page URL
    URL = "YOUR_OANDA_API_URL_HERE"

    Set XML = CreateObject("MSXML2.XMLHTTP")
    XML.Open "GET", URL, False
    XML.Send

    ' **Important:** Add code here to parse the XML or HTML response
    ' and extract the exchange rate. This will vary depending on the
    ' data source.

    ' For illustration purposes, let's assume the rate is directly in the response:
    Rate = XML.responseText

    ' Update cell A1 with the exchange rate
    ThisWorkbook.Sheets("Sheet1").Range("A1").Value = Rate

    Set XML = Nothing

End Sub

Disclaimer: This VBA code snippet is a simplified example. You will need to adapt it based on the specific data source you're using from Oanda and the data format.

Conclusion

Automating exchange rate updates in Excel can significantly improve efficiency and reduce errors. By leveraging Excel's "Get Data" feature or VBA scripting, you can link your spreadsheets to Oanda.com and update the rates on demand, giving you complete control over your financial calculations. Remember to prioritize data accuracy and adhere to Oanda's terms of service when implementing these solutions.